﻿Big Tits Theory
by Pan



Genre: Incest
Status: Completed
Published: 2019-10-21 18:17:03
Updated: 2019-11-06 19:57:41
Packaged: 2019-11-17 11:27:53
Rating: Much Sex
Chapters: 9
Words: 15,394
Publisher: storiesonline.net
Story URL: https://storiesonline.net/s/21119
Author URL: https://storiesonline.net/a/pan
Summary: Marty tells his sister about a theory he has - the "Big Tits Theory" - while feeding her body-altering, mind-bending milkshakes.





TABLE OF CONTENTS


Chapter 1

Chapter 2

Chapter 3

Chapter 4

Chapter 5

Chapter 6

Chapter 7

Chapter 8

Chapter 9



	Chapter 1

Monday:

“Geez,” my brother said to me one morning, over a milkshake. “You sure are lucky...”

“Why’s that?”

My brother Marty and I had never been super close, but lately we’d been hanging out pretty much every morning. I think it’s the milkshakes - a couple of weeks ago, Marty got this machine that makes milkshakes. You wouldn’t think that making a good milkshake would be hard, but the first few he made were somehow revolting. It’s milk and flavor, right? How badly can you screw that up?

After a while though, something clicked, and he he **really** got the hang of it. I’m not kidding when I say that Marty’s Milkshakes are the single best milkshakes that I’ve ever tasted. They’re delicious, and each morning we both get up before school and he makes me a milkshake.

We’ve been using that time to hang out and shoot the shit. He’s a good guy, Marty - two years older than me, but he’s never been the dickhead older brother. We’d always just sort of lived our own lives, up until he got his magnificent milkshake machine.

Now? I guess we’re friends. I’ve been telling him more and more stuff about my life, and he’s been advising me ... not in an over-the-top or patronising way, but just brotherly older advice. It’s been super nice: I really trust him.

“Well,” he said, strangely hesitant. “It’s just...”

“What is it, Marty?”

“You’re lucky that your tits aren’t bigger.”

I scoffed at that, but then saw that he wasn’t joking.

“ ... why?”

Now it was his turn to scoff.

“Are you telling me ... you haven’t heard of the Big Tits Theory?”

The Big Tits Theory, according to my brother, was simple. In fact, more than simple - it was fundamental. He said it was a basic human fact: the bigger a girl’s tits, the more slutty she is.

Of course I thought he was kidding, but as he went on, he managed to convince me more and more ... he’d really thought this one through.

Girls with A-cups, like me, were ... well, prudes. Not sexually charged, rarely sexually active, and if we did get with a guy, it would be for a reason other than sex. Like a lot of the women in Game of Thrones - they’d sleep with men so that they could have children, or power, or for protection ... but they never just did it because they were horny.

And though I’d obviously never discuss this with my brother, his theory was pretty solid so far. I’d never fooled around with anyone - I was a capital-V virgin. And, honestly, I’ve never really felt the urge to. I mean, it would be nice to find a guy who liked you, and maybe hold hands and kiss and all that, but sex? That was grown-up stuff.

I’d heard my friends talking about masturbation and boys going down on them, and it had all ... well, it had all sounded pretty gross, to be honest.

B-cup was a “normal girl” he said, not even realizing the insult in his word-choice. They got urges, they masturbated, and maybe if they were in a long-term relationship, they’d fool around. C-cup was (again, his words) like “girl PLUS”. They were often horny, and it wasn’t super hard to get to second or third base.

D-cups, though ... according to my brother, they were the motherlode. D-cups were the kind of girls who go out on the town, looking for one-night stands. If you make eye-contact the right way, they instinctively fall to their knees and their mouths pop open ... you know the girls who hang around bands all the time, groupies? They’re almost exclusively made-up of D-cup girls.

“And so,” he’d said, finishing the last of his milkshake, “little sis - you are extremely lucky that you’re ... well.”

He’d gestured to my chest, and I’d glared at him while slowly sipping the milkshake that he’d made me.

“I mean, if you were any other girl, I’d want you to be a C or higher. But my little sister ... believe me, I wouldn’t have you any other way. You’re what, a B?”

“An A,” I’d replied quietly, almost embarrassed to admit it. Let’s face it, no girl likes being flat-chested.

“Oh,” he said sympathetically. “Well ... don’t worry about it. You’re only 18 ... maybe you’re just a late bloomer?”

**Yeah right,** I’d thought, and gone upstairs to change for school. Looking in the mirror, I’d sighed. An A-cup. Doomed to a life of never wanting sex. The “A” could just as easily have stood for “asexual”.

I shook my head - what was I worrying about? Marty probably didn’t even know what he was talking about. “Big Tits Theory” ... utter bunk.

But on the way to school, I started thinking about it, and I couldn’t think of a single example to prove him wrong ... all of the sluts in my grade: Cindy, Stella, Ruth ... they were also the girls with the biggest tits.

Sure, that could have been coincidence, or it could have been self-selecting (girls with big tits get more attention, and so they just have more opportunity to fool around) ... but my brother’s theory held up across the whole spectrum. One of my friends I knew for a fact was a B-cup, and she’d only slept with her boyfriend after they’d been together for more than a year. Or Margaret - she was a large C, and she’d only been with Tom for a few weeks when they’d “done the deed”.

Staring out across the cafeteria at lunch, I wondered if my brother was right. Had he cracked the female code? In terms of evolution it certainly made sense ... it would totally explain why guys always went for the girls with the biggest boobs - because they’re the easiest lays.

That night, I wanted to ask Marty a few more questions about it, but he was out on a date. I only saw her briefly, but his wink told me everything I needed to know... 

He was going out with a D-cup.


	Chapter 2

Tuesday:

“Oh my god!” I said, for the second time that morning. “This milkshake is amazing!”

“Thanks,” Marty replied with a grin. “I’m trying some new stuff. Can you taste the cinnamon?”

I nodded, even though I couldn’t. It all blended together in a perfect combination of tastes - there could have been cinnamon in there, but I’d never have picked it out from the blend of everything else.

My nod caused an unfamiliar sensation on my chest, but I tried not to focus on it as I sipped Marty’s latest amazing concoction.

That morning, when I’d woken up, my nipples had been strangely sensitive. They weren’t sore, exactly, but there was something strange. It wasn’t until I looked in the mirror that my eyes had boggled, and I’d sworn in shock.

Somehow, overnight ... my boobs had grown.

I reached up and pinched them - not only had they grown, but for the first time, I understood why women let men suck on them! I wasn’t rolling around on the floor with pleasure or anything like that, but the right sensations, the right touch ... I could totally see myself getting off on this.

Getting off ... my eyes widened as it dawned on me what this meant. I was ... well, I couldn’t tell, not without measuring, but ... I was pretty sure that I was a B-cup! And according to my brother’s theory, that meant ... I looked around to make sure that no one was watching - a strange thing for a teenage girl to do, alone in her room, but I was exploring new territory. The door was closed, and so I lay down in my bed, shut my eyes, and imagined one of the singers from my favourite boy-band standing over me, smiling, taking his top off for me ... To my delight, my vagina glistened, and my fingers naturally began stroking up and down my sensitive pussy-lips, instinctively discovering what I liked, what felt good ... I was - I was masturbating.

And I loved it!!

But before I could get too far into my fantasy, there was a knock on my door, and my eyes opened in shock as I was instantly teleported from the land of sexy male musicians touching my private areas... 

“Sis?”

It was Marty.

“Sis, are you up? I’ve got a milkshake waiting for you!”

Reluctantly, I got up, put a top on, and joined Marty in the kitchen. Self-exploration would have to wait until later.

After the most delicious milkshake I’d ever had in my life, I went back upstairs. I found myself just staring at my tits in the mirror - they were no more than a handful, at most, but I’d heard boys saying that anything larger was just a waste ... and I certainly wasn’t complaining. I couldn’t believe I had tits!

I was even tempted to skip school, just to spend the day exploring the new sexual feelings coursing through my body, but I knew it wasn’t worth it, and so quickly got dressed and left for school.

When I arrived, something else hit me - I was a B-cup girl, which meant that if I found someone I liked, and we dated for a while ... we could have sex. And it would be good!

Suddenly, all the men around me weren’t just men, they were potential boyfriends, potential partners. Gary, who had always been extremely friendly - perhaps he’d been flirting this whole time, and I just hadn’t noticed. Paul, who was in my home economics class ... Timothy, from physical education ... after a while I got so into it, I even started looking at some of the younger teachers differently.

The day passed in a blur - I barely focussed on my schoolwork. Where yesterday I’d been looking out over the cafeteria, examining and analysing the girls based on bra-size, now I was doing the same for the boys ... today, I decided, I’d rank them, and tomorrow I’d start my way down the list. Perhaps I’d even learn to flirt, something that had always escaped me in the past ... After school, I raced upstairs and slammed the door. Finally, I knew what it was to be a woman - looking at all those boys today had actually managed to get me all hot and bothered, and now, alone in my room, I was going to do it.

I was going to have my first orgasm.

One hand reached up and grabbed my left tit - it actually felt larger than it had that morning, but perhaps that was just a side-effect of being turned on - and started drawing small circles around my nipple. My other hand reached down, and just like earlier in the day, started stroking up and down my pussy-lips. I hadn’t taken my panties off, not yet, and when I glanced down, I was far too delighted to see that my wetness was visible through the thin fabric.

Shutting my eyes, I imagined one of the boys that was definitely in my top three - Patrick, one of the footballers. I imagined asking him out, him saying yes ... us going on a few nice, chaste dates ... and then, after we’d been together for a month or two, driving out to a make-out point, and kissing each other.

Kissing each other passionately.

As my fingers pushed my panties aside and made direct contact with my kitty, I thought about what would happen next: things would keep on escalating. Maybe after we’d been together for six months, after we’d gotten each other hot and horny time after time, we’d find ourselves wanting to go further, to second ... maybe even third base.

I pictured his cock slipping into my mouth, my tongue circling his head. I wondered if he’d be interested in going down on me, feeling his lips where my hand was now. Perhaps he’d like to ... finger me. I’d heard the term, but never before truly understood the appeal.

Perhaps one of his fingers would slip between my lips, as my own fingers were doing now. Would he know how to find the clit ... it seemed so obvious to me, but that was because I’d accidentally brushed against it, and felt how sensitive it was.

Breathing heavily, I swallowed. I was getting close, and I knew exactly what would push me over the edge. After we’d been together for a year, maybe more, then Patrick would ... take my virginity. He’d do everything right, carry me upstairs into my bedroom, on a weekend when no one was home. We’d fool around for an hour before we built up the courage, and then ... His cock (which I was already imagining in great detail) would part my pussy-lips, and he’d enter me. He’d enter me, over and over again, until we both climaxed ... I could almost hear the sound of his pleasure, and my fingers reached up and rubbed the small nub that I’d been avoiding. My hips thrust forward as I experienced my first orgasm, cumming softly at the thought of my long-term future boyfriend taking me for the first time ... As the last waves of arousal subsided, I sat up, a glow on my face that hadn’t been there before. I was a woman, and tomorrow ... I was going to go out and get myself a man.


	Chapter 3

Wednesday:

“No...” I said to myself in shock. “No, this ... this can’t be.”

Somehow, overnight, my breasts had grown another cup-size. I was no longer the B-cup that I’d been so happy with the previous morning (and **extremely** happy with the previous night) - I’d somehow grown two cup-sizes in two days. I’d gone from being the nice, sexual, respectable girl ... to being what Marty had called “Girl Plus”. Not a compliment, not when you knew what it meant.

C-cups ... were easy. Not nearly as bad as D-cups, of course, but certainly not prudes. As someone who had been as un-easy as possible just a few days ago, I was barely adjusting to having a normal, healthy sex-life ... now I was going to be **easy**.

I stood in front of the mirror in shock, until the knock on the door pulled me out of my stupor.

“Sis?” Marty’s voice said, and when I didn’t reply, the door began to open.

“Coming!” I said, quickly turning and putting a shirt on.

I’d gone to school yesterday without a bra - I hadn’t had a choice. Originally I’d been planning to go after school and get myself a nice, new B-cup ... but it looked like my sudden growth spurt wasn’t over yet. There’s only a certain tit-size that you can get away with going braless, and let me tell you - it certainly isn’t C.

I decided to wear three layers - surely, I thought, that would be enough to hide my nipples ... but as I slipped a singlet on, I shuddered with pleasure and realized that I had another problem.

The sensitivity of my nipples had apparently doubled along with my cup-size, and as the material came into contact with them, I discovered that they were quickly becoming my most erogenous zone. Every time I moved, the thin fabric brushed across them, and try as I might, I couldn’t help but pause and enjoy the feeling.

On top of the singlet I wore a tight T-shirt, and then a thick woollen jumper above that. It wasn’t my most flattering ensemble (although I had to admit, having C-cups made almost anything look good) but it hid the constant-hardness of my nipples, and as long as I was careful with how I moved, I only stimulated myself every two or three steps.

**If that’s how good my new boobs feel,** I thought to myself as I descended the stairs, pausing in pleasure sporadically, **I can’t wait to see what masturbating as a C-cup is like...** I tried to decline my brother’s offer of a milkshake - I wanted to leave as quickly as possible, and try to buy a new bra from the mall, anything that would help keep my nipples under control - but he was so excited about some new combination of flavors that I eventually gave in, and sat down to try it.

“Stella loved it,” he said, and I looked at him with confusion.

“Stella from my school?”

“Yeah,” he said casually, avoiding my eyes. “I went out with her last night. She’s really ... fun.”

I couldn’t stop a smile from passing over my lips.

“Fun, is she?”

Marty looked at me and just grinned in response.

After a few sips of Marty’s new milkshake (which somehow managed to be even more delicious than the one he’d made yesterday) I tried to casually bring up the Big Tits Theory.

“Hey yeah,” Marty said, glancing at my new boobs. “I was going to ask you about that...”

“Oh, it’s, uh ... I thought it might be a good idea to pretend to have larger boobs than I do. You know ... get the boys in. Advertising.”

“False advertising,” Marty said with a laugh, nodding. “Classic A-cup. What did you want to know?”

“C-cups,” I said firmly. There was always a chance that my boobs hadn’t finished growing yet, but I’d cross that bridge when I got to it. “What can you tell me about them?”

“Well,” he said slowly. “I mean, my speciality is D-cups, but I can tell you a bit. Think of them like ... like shy guys. Shy guys are always horny, and if they think someone likes them, they’ll make a move, and go pretty much as far as the other party wants. They won’t sleep with someone they’ve just met, but who’s going to turn down a b-job? They’re not freaks ... but they don’t really play hard-to-get, either.”

I nodded. Everything he’d said made total sense to me - the nipple stimulation had ensured that I was horny from the minute I put some clothes on, and yeah ... it definitely wouldn’t take much for me to take those clothes off again!

I thanked Marty for the milkshake, looked at the time, and cursed. I’d missed my chance to go to the mall ... in fact, I’d have to run if I was going to get to school on time at all.

And running with my new tits was definitely not something I was looking forward to.

* * *

I managed to get through the first half of the day without doing anything to embarrass myself. Although, honestly, I was finding it harder and harder to work out what **would** embarrass me.

Boys had noticed. Of course they’d noticed, they were boys ... and remembering what Marty said, I acted the part of the shy guy. I didn’t initiate anything, not even when some of the top contenders from yesterday’s list came to say hi.

But it was mid-June, and way too hot for three layers. I’d been at school for less than an hour when I caved, and took the woollen jumper off - I was drowning in sweat, and knew that I wouldn’t last the rest of the day buried under so many layers.

As I’d feared, without the jumper, my nipples were clearly visible. The T-shirt I’d bought back when my breasts were tiny was stretched obscenely by my new C-cups, bulging out and making it nearly impossible for any boy to keep his eyes on my face.

Worst of all, the stimulation hadn’t gone down, and drawing so much male attention did nothing but accentuate it. And so as soon as the bell rang for lunch, I got up out of my seat and ran (causing a bouncing that I’d seen on other girls but never expected to experience myself) straight for the bathroom to get myself off.

**How odd,** I thought, **that something I’d never done before yesterday was suddenly so vital to getting through the rest of the day.** And vital it was - as soon as I was in the stall, my shirt and singlet were up against my neck, and my pants were down.

Pinching and groping at my new tits, I moaned loudly. It felt so ... so **good**. Yesterday’s session was like a light drizzle - this was more akin to a heavy rain. I plunged one hand down into my panties, and went straight for the clit - no foreplay was necessary. As I pinched and tugged at my left nipple, two fingers entered my virgin hole, over and over, and my thumb ran over my clit, lubricated more than enough by my freely-flowing juices.

I imagined pleasing all the boys that had spent the day staring at me - I imagined them pulling me aside, taking me into an empty classroom, forcing me to my knees, and pulling their cocks out. I wanted to suck them off, all of them - I wanted to feel their cum splashing against the back of my throats, taste their sweat. I wanted them to use me.

It was that image which made me cum - just like I had the previous night, my hips bucked forward, wanting to press and push against an imaginary cock. Some part of me wanted to be fucked, I knew that ... but I was still a C-cup. Second, third base ... that would satiate me.

For now.

I deliberately avoided thinking about what would happen if my tits kept growing, cleaned myself up, and left (after checking to make sure that there had been no one else in the bathroom).

As I walked down the corridor, I felt much more relaxed than I had all morning. I was okay. I was in control. There was nothing to worry about ... It was a feeling that quickly disappeared as I noticed the stares.

Some of them (perhaps even most of them) were undoubtedly because of my new breasts. But I couldn’t stop my imagination from running wild - what if someone had seen me go into the toilets, and heard what I did in there? I certainly hadn’t put any effort into being quiet. What if they knew about the Big Tits Theory as well, and they were laughing because they knew what I was now, what I’d do.

What if they were staring because they wanted me?

That last thought got stuck in my head, and my nipples (which had been soft for a few glorious minutes) began to plump up again, and rub against the material of my underthings. I suddenly wished that I had my sweater, that I hadn’t left it in my locker ... I was conflicted, simultaneously wanting to cover up and expose myself, lift my shirt and show the world what was underneath.

**What a distinctly D-cup thought,** I reflected, before gasping as I turned the corner.

In front of me stood Patrick, champion of the school’s football team, and subject of my fantasy the previous night. He wasn’t the quarterback, but I didn’t know enough about the sport to understand why.

All I knew was that he was perfect.

Standing more than six foot tall, he towered over me ... over every woman in the school. I’d heard girls talking about him in the past, about how much they wanted him, but until my latent growth sport, I’d never understood why.

Suddenly, it all made sense. He was muscled, tall, and so dominant that just standing near him made my knees weak. Yesterday I’d fantasized about being in a long-term relationship with him, but now ... well, now I would have been happy to be face-fucked and thrown out.

He saw me staring at him, glanced down at the double show I was inadvertently putting on for the whole school, and strode over to him. I leaned on the wall, trying to act casual, aware that with every movement I made, my tits wobbled slightly, and that it would be a strong man who could resist sneaking a peek... 

“Hey,” he said, his deep voice making a chill go up my spine. “Patrick.”

“I’m, uh...” I paused, lost in his eyes, before shaking my head (again, causing motion on my chest that I knew would attract his attention) “ ... we haven’t met.”

“I’d like to,” he said with a grin, and before I knew what I was doing, I was pushing on his chest, taking him into an empty classroom, making my fantasy come true ... I knew that I wasn’t acting as shy as someone of my cup-size perhaps should, but I figured he’d definitely shown interest, and everything after that was okay, right? Besides, even though I didn’t want to admit it, I got the feeling that my growth spurt had continued into the day ... I was now, at the very least, a large C.

Patrick didn’t say much, just stood there with a cool, amused look on his face as I grabbed his head and forcibly started making out with him. Not, of course, that he needed much forcing - he reached up and grabbed my hair with one hand, reaching out and cupping my boob with the other.

I don’t know if there’s a website that guys go to learn these moves, but when he pulled my hair and tilted my head back so he could have free access to my neck, it just drove me wild. “Please,” I panted, and he let go, looking at me with concern.

“Please,” I repeated, “ ... don’t stop.”

That cocky grin appeared on his face once more, and soon his tongue was back down my throat, and his hand was once more tweaking my nipple.

I was practically shaking with need - I’d thought that getting off in the bathroom would be enough, but it seemed to have just increased my hunger, like giving a slice of bread to a starving man. I didn’t know exactly what I wanted, but I knew that Patrick was going to give it to me.

The classroom I’d instinctively taken him to was mostly disused, and the lights were off, signifying that there would be no more classes there for the rest of the day. So I didn’t fight him as he slid my pants and then my panties off, and the flow of juices from my most private parts ensured that his hand faced no resistance at all as he slipped two fingers inside of me, and started slowly moving them in and out.

I was writhing with desire as my body took over, and I pulled my top off, finally freeing the breasts that all day had wanted so desperately to be seen. His eyes widened at the sight of them, and I reached down to feel his hardness.

**I did that,** I briefly thought, before reluctantly pulling his finger out from my wetness, and slithering down to his knees.

I’d never seen a cock before ... in fact, except for one sleepover with my girlfriends where they’d insisted (despite my opposition) on watching a dirty film, I’d never even **seen** a cock before. But I listened to my boobs, obeying my instincts, and licked it a few times before moving the whole thing into my mouth.

Patrick seemed to know what he was doing as well, and his hands never let go of the sides of my head - he guided my mouth, as well as thrusting back and forth.

**He’s fucking my mouth,** I thought, wide-eyed and horny. *He’s fucking my mouth ... I’ve never even kissed a boy before today, and now Patrick Kent is fucking my mouth...”

One of my hands reached up and started playing with my needy nipples, while the other went between my legs, stroking my clit. I didn’t want to come before him - that, I somehow knew, was rude - but I also knew that if he didn’t hurry up, I’d have no choice.

I kept my eyes wide opened, staring up at Patrick’s face as he smiled, enjoying the feeling of fucking the face of a girl he’d only just met a few minutes ago. I tried to avoid thinking about how full my mouth felt, tried to think about anything other than the taste of his cock, how good it felt to be orally fucked by such a sexy, dominant male ... but I was right on the cusp when he grunted that he was cumming, and I stimulated the underside of his cock with my tongue, the best I could.

I don’t know what I was expecting, but as his cum shot into my mouth, its taste surprised me ... until I came, putting all other thoughts out of my mind.

When I opened my eyes, Patrick was already redressed, staring down at me, that ever-present smile upon his face. I went red when I realized what he’d seen - my fingers, buried deep inside my hairy pussy ... my tits, wobbling and jiggling as my hips thrust upward.

It must have been obvious how much I wanted to be fucked ... but not today.

No, I wasn’t that kind of girl. Not yet.


	Chapter 4

Thursday Morning:

I woke up, and was unsurprised to discover that my bra, despite being brand new, didn’t fit.

After school the previous day, I’d finally made my trip to the mall. A quick fitting had confirmed my suspicions - I was a large C, but still a C-cup. I’d put a bra on, breathed a sigh of relief when it relieved the stimulation from my nipples, bought it and returned home just in time to see Marty off on another date.

I was getting pretty good at estimating bra-sizes by that point, but I didn’t even need to - he mouthed “D” to me as he left. She looked strangely familiar, but it didn’t click until a few hours later - it was one of Marty’s old teachers. She’d been at the school when I started, but I’d never had any classes with her, and she’d left to get married a few months later.

Oddly enough, in my memory she was extremely flat-chested ... but of course that had been before I paid attention to such things.

I’d spent the rest of the evening masturbating, stopping only to try on my bra and sigh in relief when it still fit. It was increasingly tight, yes, but I could definitely still get it on ... until I awoke the next morning.

I barely managed to squeeze into one of my shirts - my huge new tits filled my top so much that it barely even covered my midriff. That sort of look with pants wouldn’t have made any sense, so I wriggled into one of my old miniskirts, and went downstairs to pick Marty’s brain.

“Wow!” he said when he saw me. “Sis, are you...”

“I don’t want to talk about it,” I said, and unable to stop himself from staring at my tits, he just nodded. “D-cups ... what do you know about them?”

“A lot,” he said, one eyebrow raised, still talking to my breasts. “Are you... -”

“Not now, Marty!” I interrupted, stamping one foot petulantly. The motion rippled through my body, and made my tits bounce ... Marty’s attention was beginning to make me feel warm, but I **really** didn’t want to think about that right now. “Please! I need ... I need to know.”

“Well...” he said, pulling up a stool and placing a milkshake in front of me. “Where do I start? D-cups are easy ... really easy. Like, look at them the right way and they’ll fuck you easy.”

I took a sip of the impossibly delicious milkshake and swallowed nervously as he continued.

“There’s pretty much nothing that they won’t do - anal, pearl necklaces, spanking ... you name it, they get off on it. Oh, and they take any excuse ... and I mean **any** excuse to get their kit off. They enjoy themselves, too, in my experience. They cum like firecrackers. The smallest thing will set them off. Yeah, you gotta love D-cups ... they’re always up for it.”

I nodded, and then a horrible thought came into my head.

“And ... Marty?” I asked softly.

“Mmm?”

“What ... what do you know about E-cups?”

“Oh, E-cups are total freaks. I tend to not even mess with them ... when you get up to E-cups, you’re looking at porn stars, that sort of thing. There’s **nothing** an E-cup won’t do ... hell, they’ll probably even fuck their own family, given half a chance.”

My eyes widened in shock. I had to find out why my tits were suddenly growing, and stop them ... before it was too late.

I gulped down my milkshake, and ran out the door, feeling Marty’s admiring eyes on my legs as I left.

The decision to skip the first few classes of the day was an easy one, now that I knew what I was. Hell, I would probably have gotten to school and dragged some boy into the bathroom with me, and just let him bang me throughout the first few classes anyway ... the thought was appealing, but I had to remember - I was on a mission.

First stop: the mall.

I ran into the lingerie shop I’d visited yesterday, avoiding eye contact with everyone. My cheeks burned red as I realized that everyone, everyone was staring at the girl with the huge rack and the long legs and the high heels - why had I worn high heels? She was the kind of girl who you could tell was easy, a girl that drew everyone’s attention ... And that girl was me. If I looked up, I knew that I’d catch some guy’s eye, and a few minutes later we’d be in the back seat of his car, and I’d be getting pounded like I so desperately needed ... No. Had to concentrate. I got into the lingerie show, relieved to find that it was a girl at the counter. She looked at me with a strange mix of disgust and professionalism, but it was obvious that she didn’t want to fuck me. Which was almost a pity, because I’d never been with a ... focus! Focus. I was here to get a bra.

I grabbed the first D-cup that I could see, and in the changing room, sighed with relief. It fit. A tiny bit snugly, but I was definitely a D-cup. I went to buy it, but couldn’t resist going with the more transparent option ... if my shirt were to accidentally come off, I’d hate to be embarrassed by my boring brassiere, after all.

Once I was out of the bra store, my tatas receiving slightly more support, I relaxed slightly. Next stop: a medical professional.

As I marched into our family doctor’s office, I was relieved to find that he hadn’t replaced his secretary - for as long as I’d been going (which was since I’d been a little girl) Ms Weiser has manned the front desk. A part of me had been worried that the professional older woman would have been replaced with someone younger, maybe a body-builder working at the doctor’s office part-time.

I’d feared that as soon as I entered, he’d throw me a smouldering glance, tell me that the doctor was out, and that I’d uncontrollably step toward him, our eyes locked, until I leaned across his desk, showing off my now-ample cleavage ... he’d brush everything aside, expense be damned, and throw me down, kissing me passionately, and fucking me so hard that I’d have trouble walking afterward ... So when I saw that my fantas- ... that my **fear** was misplaced, I sat down, disappointed, and waited for Dr Lorne to see me.

“It’s been too long,” the doctor said as I entered. In fact, he’d seen me just a month beforehand, but one advantage that I was discovering a fuller chest gave you was that people tended to remember you a little better.

“It’s ... well, I’m a bit worried about the growth spurt I’m going through,” I said, and at the doctor’s quizzical look, gestured to my chest.

“Ah, yes,” he said, putting on his glasses and having a look. “Well, probably nothing to worry about ... a lot of girls are just late bloomers in that regard.”

I giggled at that, and Dr Lorne gave me a strange look. My eyes opened in innocent shock - I genuinely had no idea why his comment had drawn a chuckle. Dr Lorne was just suddenly so ... attractive. Authoritative. He must have been thirty years older than me (at least) but he was still a man, and what’s more, one who was staring at my chest ... A man staring at my chest, I was quickly learning, was my **favorite** kind of man.

I arched my back, trying to give him the best possible look at my new assets. My “late bloomers”, I thought with another giggle. If I was going to get to the bottom of this, then a medical professional was obviously the way to go... 

“If you’d feel more comfortable,” Dr Lorne said, “I could get a nurse in here to look. But if you don’t mind, I’d like to have a look - check for stretch-marks, that sort of thing.”

“Oh no, doctor...” I said, inadvertently dripping sex with every word. “I’d **love** for you to have a look.”

That strange look returned - Dr Lorne pursed his lips, and after a few second’s thought, came to some kind of silent decision.

“If you wouldn’t mind,” he said, gesturing to my T-shirt.

A part of me was tempted to rip the shirt off - it was already straining - but if I was going to work out why my breasts had abruptly started expanding, I knew I had to hide the real reason I was here. No, wait ... finding out why my breasts were growing **was** the real reason I was here. Wasn’t it? Everything was suddenly so confusing.

The shirt lifted my boobs slightly as I pulled it off, and I was gratified to see Dr Lorne staring at them as they fell, bouncing slightly as they settled back into place. He continued to stare at them, as if entranced, as I reached behind myself and undid my bra. It fell away, and my perky pink nipples came into view - Dr Lorne shifted slightly in his seat, and a cheeky grin appeared on my face as I realized that though he may have been a medical professional, he was also human.

“What do you think, Doc?” I asked, lifting each one individually, and then letting them go. My fingertips brushed across my nipples, and I stifled a moan of pleasure.

“Well...” he said, sounding slightly flustered. “How long have you been going through this growth spurt?”

I thought for a second - the math was surprisingly hard. Monday, Tuesday, Wednesday... 

“Three days,” I said, and he looked at me with one eyebrow raised.

“Three days?”

“That’s right, sir.” I said, the last word slipping out unprompted. “On Monday, I was an A-cup...”

Dr Lorne had been jotting notes down in a small pad, but as I spoke, he slammed it shut, and threw me a dirty look. Not the fun kind of dirty, either.

“Oh, please ... are you trying to tell me that your breasts have grown four cup sizes in three days?”

“Three,” I said. “I a D-cup, not an E-cup.”

**... not yet,** I added mentally.

“Please, doctor, you’ve got to help me ... I can’t just keep on growing.”

“My dear,” the doctor said, continuing to look at me unhappily. “First of all, growing three cup-sizes in three days is medically impossible. Secondly, if you **had** grown that much that quickly, you’d have stretch-marks. And if you have a look here...”

The doctor reached out and grabbed my left breast, moving it left and right. My eyes fluttered back in my head - it felt so **nice** to have someone else touching me, and without meaning to, I let out a small whimper. I hadn’t gotten off all day, and between all the men at the mall, and the male model that Dr Lorne hadn’t hired, and now him ... a real man, touching me ... I needed release.

“ ... you can see that there’s no sign of any growth at all.”

With that, he stood up, and gestured for me to put my clothes back on.

“Now, if you’ve finished wasting my time, I do have other patients...”

I don’t know what I must have looked like at that moment. I’d accidentally slipped into fantasy - acknowledging my own arousal had been a bad idea, because my mind was now racing with different ways that I could find release. I could ask the doctor to watch me get myself off, to “make sure I was doing it right.” He could help me out, teach me, take me ... But whatever expression I had on my face, Dr Lorne must have interpreted it as anguish or fear. He sat down next to me, on the thin bed.

“Unless,” he said softly, “that’s not why you’re here...”

Looking back, I can see that he was trying to be sympathetic. He was worried that I was having trouble at home, or perhaps that I was pregnant ... I don’t even know what. But in that moment, at that level of arousal, I interpreted his words as a come-on.

And I, after all, was a D-cup ... like all D-cups, I was incapable of resisting a come-on.


	Chapter 5

Thursday Afternoon:

It had been surprisingly easy to seduce Dr Lorne. He was a professional, through and through, and I suspect that most attempts to make him act so improperly would have failed ... but there are few men in the world who can resist a horny topless 18-year old girl who’s throwing herself at you, and Dr Lorne certainly wasn’t one of them.

My mouth descended on his, and after a few seconds of struggle he allowed himself to melt into the kiss, wrapping his arms around me and running his hands up and down my back.

“Oh, Doctor...” I moaned, and he tried, briefly, to distance himself from me.

“We really shouldn’t...” he said, but I took his hands, placed them onto my plump breasts, and writhed in pleasure as he allowed himself to enjoy the feeling of two huge, teenage tits in his hands.

A few seconds later, his pants were around his ankles, and my hand was on his cock.

His cock ... despite my first ever sexual activity being less than twenty-four hours ago, it felt like it had been familiar since I’d had the familiar feeling of a nice juicy cock in my hands. I wanted to taste it, I wanted to play with it ... but more than anything, I wanted it to fuck me. I wanted to be fucked by my doctor, for the first time ... he was there when I was brought into the world, and somehow, in my head, that made it okay for him to be the man to take my virginity.

The idea was only in my head for a few seconds before I was frantically pulling my panties down, bending over the patient bed, and looking back at the doctor.

“Please,” I said as sweetly as I could. “ ... don’t be gentle.”

Dr Lorne’s eyes widened, and I reached behind myself to guide his cock into my entrance.

It was everything that I’d dreamed it would be. His firm cock slowly pushed against my lips, parting them, finding the wetness inside of me. He kept on pushing forward as fireworks exploded in my head - I felt so full, I felt so good ... I felt so useful. I was a D-cup, and that meant that I couldn’t say no ... not, of course, that I wanted to.

Finally, his cock was inside me, all the way. He stayed still for a few seconds to let me adjust - I’d never felt anything like it. I squirmed at the sensations that his member caused in me, and sighed with pleasure as he started pulling out of me again.

“Oh, Doc...” I said, and looked behind me to see if he was enjoying himself. His eyes were closed, and if his hands hadn’t reached around and started pulling and tugging on my tits, I would have worried that it was because he didn’t find me attractive. But then he pushed forward again, and I stopped worrying ... about anything.

It didn’t take the good doctor long to cum. As a medical professional, I was slightly surprised that he wasn’t more concerned about protection, but I suppose he wasn’t the type to put a condom in a gift horse’s mouth, or however that expression goes. I orgasmed just before he did - every time he thrust into me, I clenched, and my clit went wild with delight. I couldn’t believe how good being fucked had made me feel, and I think that my clenching pussy and gasps of pleasure were what set Dr Lorne off as well.

After we were done, he pulled out, and started to stammer an apology. I wasn’t really listening - I was sitting up on his bed, legs spread, looking at my pussy. If I squeezed in a certain way, cum dripped out, and it was one of the most beautiful things that I’d ever seen.

“Are ... are you on the pill?” he asked when I didn’t respond, and I just shook my head and giggled.

“It would probably be a good idea, though,” I said in reply. “Because I’m planning on doing a **lot** more of that.”

And I did. After pulling my panties back on, and waltzing out of the doctor’s office with a prescription for birth control in my hand, I **meant** to head straight for the pharmacy, but a particularly attractive construction worker caught my eye, and after I’d approached him and asked why he hadn’t cat-called me, a few minutes later we were tumbling into a half-built room, his pants around his ankles, and my bra in his hand ... After the construction worker, it was a businessman I passed on the street, then a man selling hotdogs who knew where the nearest public toilets were, and then taxi driver who I’d hailed because I thought he looked cute. Finally, when I got the taxi-driver to drop me off at school (leaving him my extremely damp panties as a tip), my pussy was starting to feel a tiny bit sore.

**Another side-effect of having big boobs,** I thought with a sad shake of my head. **Small-chested girls have no idea how easy they have it...** When I arrived in school, lunch was just wrapping up, and I couldn’t help but notice, as I wandered into the cafeteria, how many stares I was drawing. The uncharacteristically short skirt, the ruffled sex-hair, the unrestrained breasts... (I’d offered the construction worker a blow-job in return for getting my bra back, but he was exhausted after our two quick, messy fucks. He’d offered to just give it back, but that didn’t feel like a fair transaction to me, and so I’d let him keep it.) I’ve got to tell you, it put a bounce in my step, and as my heels clacked across the floor, I found myself heading straight for Patrick and his friends.

“Hey,” I said, sitting next to him and putting one hand on his leg. “Can I ask you a favor?”

The huge footballer looked at me with a half-smile on his face, and glanced around at his friends.

“This is ... uh...” he said, attempting to introduce me, but I dismissed the formalities with a wave.

“It doesn’t matter. Could I speak to you? Alone?”

He was already getting up, but I wanted to make my point, so I leaned over and whispered in his ear.

“I don’t really want to talk ... it’s about sex.”

A few minutes later, Patrick had found us another empty classroom with the lights off, and my arms were in his hair, his tongue halfway down my throat.

“I want you...” I moaned, and knelt down in front of him. “I need you...”

This time, however, I didn’t take his cock in his mouth - though God knows I wanted to. Instead, I just jerked him off. **I’ve never actually done this before** , I realized as I stared adoringly at his cock, while my small hand pumped it over and over. It was beautiful, in many ways - seeing his veins pulse and the head of his cock intensely throb as he got closer. Finally, recognising that he was close, I turned around and aimed him at myself, hitting my own rear entrance with his seed.

“What was that about?” he asked as I smiled with triumph. I looked up at him, and told him what I’d really brought him here for.

“I want to you to take my ass ... but I’ve never done it before. Can you help?”

His cock plumping up again in my hand was all the reply that I needed. From my conversation with Marty that morning, I knew that anal sex was something I was expected to do a D-cup, but that wasn’t why I was so interested ... honestly, it just seemed exceptionally practical. My pussy was exhausted, after all the men I’d taken, but I wasn’t ready to stop yet - I wasn’t even close.

The ass was new territory, which excited me in itself, but more importantly, it meant that I could probably take another four or five men before having to call it a day ... at least.

In retrospect, I’ve no evidence that Patrick knew what he was doing, but if it was his first time as well, he certainly hid it well. He didn’t just shove it in, like a lot of men would have - he turned me around, kissed me, and then reached down between my legs and played with my clit for a few minutes.

My pussy was sore from the day’s pounding, and my clit was slightly desensitized, but his fingers running over the slick nub still felt amazing, and when his other hand started gently twisting and pulling my nipple, the combination sent ripples of pleasure through my whole body.

He leaned in and started talking directly into my ear:

“You like that? You like your little body being used by a big, strong man?”

I just nodded, and gasped as he roughly pulled on my right nipple.

“You’re such a dirty little slut ... I can feel that I’m not your first man of the day, you know that? You’ve had someone else cum inside you, haven’t you?”

I nodded again, unable to think clearly enough to lie. A part of me was worried that he’d be grossed out, knowing that he was touching another man’s seed, but when he didn’t seem to react, I threw my head back and took another ragged breath as I realized what a slut I’d been that day.

“More than one man?”

I nodded.

“How many?”

“Five,” I croaked, and felt Patrick bite my neck at the answer.

“God, what a dirty little whore you are ... and now you want to be fucked in the ass, by a boy who you only met yesterday. You’re a filthy little tramp ... and I’m going to use you like one.”

Without me realizing what he was doing, Patrick had turned me on and utterly relaxed me. He kept talking dirty to me as his left hand moved behind me, lubricated a few fingers on his own cum, still wet on my ass, and slowly slid a finger into my one remaining virgin hole. I was too horny to resist, and after a few seconds, a second finger joined the first.

“I’m going to take your ass,” he said, and I nodded, pleading with my eyes, too turned on to even speak.

Running his cockhead up and down my pussy a few times, catching some of the cum that was steadily dripping from my slit, Patrick waited until his cock was well lubricated, and then placed it at the rosebud of my asshole.

“You’re mine,” he whispered into my ear, and all I could do was agree ... It didn’t hurt, not nearly as much as I’d worried that it would. It was more like an intense pressure - I could feel my own ass expanding to accommodate his girth, and it felt amazing.

Honestly, everything about the situation was turning me on, and it all combined to leave me panting with pleasure after just a few seconds ... I loved being Patrick’s schoolgirl slut, I loved having him take my ass ... I especially loved the small moaning sounds he made, showing exactly how he turned he was by his girth slowly filling up my ass. He never let up - he just kept on slowly sliding forward, fucking his own cum into my ass, as I moaned and shook.

I’d never felt so full in my life. I was almost having trouble breathing, so intense was the feeling. It took more than five minutes before he was finally all the way inside me, deep within my rectum, and he leaned forward and whispered in my ear again when I felt his balls bouncing against me.

“And now,” he said, “you’re fucked.”

It would have been easy to be scared, but my nervousness just turned into arousal as he pulled almost the whole way out, and then plunged his thickness inside me, again and again. He didn’t go easy, and I didn’t want him to - at one point, he put his hand over my mouth, just to stop the wailing of pleasure and dirty words that I was emitting.

The stimulation was unlike anything else I’d ever experienced - it wasn’t like being fucked, although it certainly contained the same elements of being repeatedly filled up and empty. The rubbery feel of his cock on my ass was nice, but it was the pure **dirtiness** of what we were doing that was really getting me off.

I was getting fucked in the ass. I was a little schoolgirl ass-slut, and I was loving every second of it.

It was less than a minute before I felt my first orgasm beginning to build - as if he knew my body as well as I did, Patrick increased the stimulation on my clit. He’d never stopped manipulating it, not for a second, and now he could feel that I was getting close to cumming, he rubbed it faster.

“Are you going to cum?” he hissed in my ear, and I nodded frantically. “Are you going to cum from having your first cock in your ass?”

“Oh god, Patrick...” I said, the second his hand pulled away from my face. “Please...”

“Cum, my little slut,” he spat, and it was all that I’d been waiting for - my climax seemed to go on forever. Patrick didn’t let up, he kept ramming my ass as I saw stars, and when I was done, I realized that he’d been filling my ass with his seed as I came.

I collapsed onto the floor of the empty classroom with a smile, and when I opened my eyes, Patrick was looking down at me. I could imagine exactly what I looked like - skirt bunched up around my waist, my huge D-cup tits exposed to the world, cum dripping out of both my holes ... Patrick, in contrast, hadn’t even gotten undressed. He didn’t say anything as he left, and it was a few minutes before I had the energy to get up and return to class.

Now that I knew what I was doing, I wondered how many more men I could take in my ass before I got too sore to continue ... I truly loved being a D-cup.


	Chapter 6

Friday Morning

I woke up with two worries: I was afraid that my holes would still be sore, and that my tit-size would have grown once again ... I was half right.

The D-cup bra that I’d bought yesterday was already too small for me, but my ass and pussy felt great. I pirouetted in front of the mirror, admiring my ample rear - had it, too, grown? - and wondered why I wasn’t sore. Maybe Marty would be able to ... Marty.

The second that my brother’s face popped into my head, my pussy grew wet, and my nipples perked up. I was an E-cup now, at the very least, and that meant ... oh god.

I was a freak. I was the kind of girl who’d sleep with my brother without a second thought. Hell, I’d only been awake for a few minutes, and already the idea was incredibly appealing ... Collapsing backward onto my bed, I tried not to think about my brother in a sexual light. He was just my brother, I told myself, and just because my breasts were one size bigger was no reason to stop thinking of him as a sibling ... all I had to do was remember that he was just my sexy older brother, and nothing more.

Wait, no. Not sexy. That wasn’t what I was trying to ... I shut my eyes and took a deep breath. Here was what I was going to do: I was going to get up, go downstairs, and sit down in front of my brother. I was going to try to ignore the way he’d inevitably stare at my tits, or the way that my body would respond ... I wasn’t going to let his long, lingering glances at my chest affect my behavior.

I certainly wasn’t going to pull my shirt up and let him have a look. My body was **not** there to please my brother, and when I saw the outline of his erection pushing against his jeans, I wasn’t going to get down on my knees and fish it out, wrap my lips around it, and let Marty fuck my face until he was shooting his precious, precious cum deep into my throat ... Somehow, while telling myself what I wasn’t going to do, my hand had slipped between my legs, and started stroking up and down my sensitive pussy-lips. At least, I thought, my other hand was just resting casually on my breast, and not pulling at my nipples ... although, of course, my new E-cups were apparently so sensitive that just resting there was enough to get me excited.

A few seconds later, I was cumming around my hand, wondering if my brother liked going out with D-cup girls so that he could take their asses. After Patrick and I had finished up in the empty classrooms, I’d managed to persuade two more footballers to sneak away with me and take my ass, and then when I’d gotten home, I’d noticed my forty-year old neighbor staring at me as I walked down the sidewalk.

Staring was rude, but somehow if felt like it would have been **more** rude not to take him inside and make him fill my ass up with his seed. Twice.

After that, it had been a relatively quiet evening. I’d spent slightly too much time experimenting with various phallus-shaped objects around the house, and had quickly discovered the delight of double-penetration. Believe me, you haven’t known masturbation until you’ve had a cucumber up your butt while slowly sliding a glass rolling-pin inside your freshly-shaved pussy ... I shook my head. I was getting distracted. I’d had a nice morning masturbation session, and that, surely, would be enough to ensure that I could hang around my brother without getting fixated on the long, smooth cock that he was hiding beneath his pants ... Just as I’d expected, Marty stared at me as I descended the stairs. I was wearing a vest - normally it would be worn over a shirt, but none of my clothes would fit over my enormous new bosom, and so I’d decided to wear the vest by itself. It didn’t expose anything ... unless, of course, I moved.

(I was making sure to move as much as possible.) At the back of my wardrobe, I’d managed to find an insanely short skirt ... actually, I believe I may have bought it to use as a belt. Whatever the original intent, it really showed off the curves of my ass, and my pussy mound. It went really well with the platform shoes that I’d borrowed from Mom’s wardrobe - I don’t think she’d worn them for more than twenty years, but luckily for me, she never throws anything away.

Marty gaped at the sight of me, and when I was at the bottom of the stairs, I wrapped my hands around his torso, pulled him toward me, and passionately kissed him good morning. For all his smooth moves with his nightly dates, he didn’t seem to have anything to say to that, and it was only when I pulled out of the kiss that I remembered that a few minutes of making out **wasn’t** our standard sibling greeting ... Crap.

Reluctantly removing Marty’s hands from my mostly-exposed ass, I sat down on the stool, and tried to think of what I’d have done on any other day. My tits were interfering with my thinking, however, and making it hard to remember what was normal and what wasn’t. A nice, normal, sister-to-brother blow-job? Did he normally spank me, to break the ice? Or did we just skip the formalities and go straight to him sliding that cock inside his sister’s cunt, pumping in and out until I was full of his cream ... I shut my eyes and tried to remember what Marty’s cock tasted like. I could imagine it easily enough, but I couldn’t **remember** the flavor, and that was the clue that I needed - I didn’t normally blow him.

When I opened my eyes again, I realized that my vest had flipped open, exposing my pink nipples to Marty’s touch. He was standing in front of me, caressing them in awe.

“Are they...” he said, and I just nodded.

“So you’re...”

I whimpered with need.

“Should we...”

He didn’t need to say another word. His careful fondling had brought me almost to a peak, and I knew that I had to have him inside of me. I barely cared which hole he used, falling desperately to my knees in front of him, unleashing his cock ... I was an E-cup, and that meant that I didn’t say no to anything, anyone ... I needed his cock, and I needed it now.

Marty looked down at me with a surprisingly smug look on his face as I slurped and slobbered all over his cock. He’d had so many bimbos in the past few weeks, I really hoped that I could compete ... one of his hands was still fondling my breasts, and while I desperately wanted to pleasure myself as I blew my sexy older brother, I wanted to make sure to give his hardness my full attention.

Without breaking eye-contact, I slipped his cock into my mouth, further and further. Just like in my fantasy that morning, I took his member deep into my throat, carefully suppressing my gag reflex, letting my brother fuck my face, use me as his little cum-slut ... To my surprise, he didn’t unload into my mouth as I’d been expecting, instead ordering me to turn around. He didn’t take my skirt off - there was no point - and I hadn’t worn any panties, so nothing got in the way as he slowly sunk his hard dick deep into my dripping wet pussy.

“Oh, Marty...” I moaned, as he continued to play with my nipples while fucking me over the kitchen counter. “Oh, big brother...”

With every stroke, my toes curled, and I could feel my pleasure building. As I came, Marty continued to fuck me, as if my spasms of pleasure were completely irrelevant. The thought that I was being used just served to turn me on even more, and my first orgasm had barely passed when I felt the building of another.

“I’m going to cum inside you,” he muttered, and I smiled broadly in response. I could think of nothing better than to be a cock-slut for my big brother - after all, I was an E-cup. I was good for one thing, and one thing only: servicing men, getting them off, and it didn’t matter to me who they were. If 92-year old Mr Richards across the street had even so much as hinted toward wanting me, I would have been on my knees so fast it would have made his head spin.

That would have been dirty, but it was nothing compared to this - this truly proved what a depraved little tramp I was. My own flesh and blood was inside me, fitting so snugly into my velvet pussy, one hand on my nipples, the other hand between our bodies, playing with my puckered asshole.

At the thought of Marty taking my ass, another wave of arousal crept across my body. I was sweating, now - we both were ... and I loved it. I wanted him to spit in my mouth, I wanted every one of our fluids to intermingle. I wanted him to cum in my ass ... for some reason, that held a greater taboo appeal than anything else.

I considered asking, begging him to, but I quickly realized that wasn’t my place. I was an E-cup - I got told where to take the cum, I didn’t get to decide. My genetics had conspired to make me nothing more than a little sex-slave, and I certainly wasn’t going to try to fight it any more. Anything, anywhere, any time ... My second orgasm triggered Marty’s, and I moaned with pure pleasure as I felt him filling me up with his warmth. **I’m never going to shower again,** I hazily thought, and even that was enough to turn me on a little more - the idea of spending the rest of my days covered in Marty’s sweat, full of his come ... Fortunately, I quickly worked out that never showering again would severely cut down the number of men willing to fuck me, and Marty joined me in the shower. It was there that he took my ass for the first time, while holding the shower-head against my pussy and flattening me against the glass wall. A part of me wished I could see what we looked like at that moment, and it didn’t take me long to work out that was the other part of my E-cups thinking for me, the part that wanted to be a porn star ... It was that thought that filled my head as I came: I imagined men all over the world were watching Marty fuck me, getting off while voyeuristically observing our incestuous pairing. God, I wanted to be a porn star almost as much as I wanted my brother to fuck me, and as he pounded my asshole, I climaxed again and again at the idea.

I wanted to be watched, I wanted to make men everywhere cum ... after Marty had filled my ass and left me to clean up, I decided that I’d need to find a manager, someone to take care of the business side of things. God knew that I wouldn’t be able to - I’d say yes to any offer that involved getting a cock inside me, and probably more so if they offered to film it.

I left for school in a daze, dressed in the clothes that Marty managed to find me - an outfit that one of his various bimbos had left at the house. It was important, he’d emphasized, that I didn’t get expelled for turning up to school practically naked - the clothes were tight and slutty, but they’d probably pass dress-code ... and if they didn’t, I was sure that I’d be able to wrangle a meeting with the principal, and “persuade him” to let me off the hook, just this once.


	Chapter 7

Friday Afternoon

Until recently, I’d always thought my big brother was a bit of a dweeb. Not irredeemably unattractive or anything like that, but certainly not the kind of guy who could bring a different girl home each and every night. And he continued to surprise me - I certainly didn’t have him pegged as the kind of guy who **got** women, but as if the rough fuck he’d given me that morning wasn’t enough to prove it to me, when I returned home that afternoon, I discovered that he’d bought a DSLR camera, just to take photos of me.

What a sweetie!

I immediately dropped to my knees to thank him, of course - he snapped off a few test shots of me sucking his cock, and that just made me blow him with more gusto.

**It’s probably,** I thought, as my brother unloaded into my mouth and I swallowed it down gratefully, **his knowledge of the Big Tits Theory that makes him so great with women. One look at her bra-size, and he knows exactly how to treat them...**

Take me, for example. I’d woken up that morning an E-cup - the sluttiest of the sluts, the kind of girl who can’t even say no to her own brother. Hell, as I’d proven, I was the kind of girl who would **seduce** her own brother ... poor Marty hadn’t stood a chance against what I was newly carrying around on the front of my chest.

After swallowing his seed, my brother presented me with a milkshake.

“We forgot, this morning...” he said, and I took it, immediately placing it on the bench beside me.

“Oh did we?” I asked, an innocent look upon my face. “Well, maybe we could... **forget** ... again.”

He resisted my attempts to lift his shirt up, and gestured to the milkshake once more.

“Please,” he said, “sis...”

I pouted in protest, and it wasn’t until he leaned in close and whispered “I came in it” that my face lit up. Next thing I knew, I was guzzling the milkshake down as fast as I could - I swallowed most of it, but a tiny bit spilled onto the copious amounts of cleavage that I had exposed.

“Whoops,” I said, and he just smiled in response. If he was telling the truth, and he really had cum in the milkshake, that made 5 ... or perhaps 6 ... no, 5 loads that I’d swallowed that day. Not to mention the eight I’d taken in my cunt (including Marty, that morning) and the five that had cum in my ass (again, including Marty).

It had been a busy day.

After arriving at school, it hadn’t taken Patrick long to find me. He’d given me an appreciative look, and that was all I needed - a few seconds later, I was following him to an empty classroom and letting him pound my cunt for the first time.

Once he’d cum inside me, I admitted to myself that I wasn’t going to be spending much of the day learning, and set myself a few challenges. Less than half an hour later, I was fulfilling the first - I’d managed to convince two boys to accompany me to a disused janitorial closet, and after kneeling before them and sucking one cock and then the other, I engaged in my first ever double penetration.

I suppose in a sense I’m quite sexually inexperienced - I had only lost my virginity two days earlier, after all. But “inexperienced” though I am, I can tell you that the only thing that even **compares** to DP is having my brother’s cock up my ass. They’re both such taboo acts, and I feel so used ... I don’t remember the boy’s names, but though they were reluctant to share me at first, as soon as I pulled my top off and had them sucking one glorious breast each that they agreed ... at that moment, I think they would have agreed to anything.

I came and came and came. It was almost **too** much, to be honest, and I spent the rest of the day “taking it easy” by only having one guy at a time. Teachers, students, even that janitor who caught me in his closet ... I made sure that each and every one of them walked away happy and satisfied, and when the final bell rang, I felt like I’d done a good day’s work.

After my brother took some photos of me licking the last of the milk off my own teats (there’s something you never hear about! Did you know that girls with massive tits can suck their own nipples? Honestly, I struggle to understand how any of us get anything else done... ) Marty took me upstairs, and I had my first full photo-shoot.

E-cups want to know that they’re pleasing men everywhere, all over the world ... it’s hard to explain to anyone who isn’t so well-endowed, but it’s a bit like having a great gift. Beethoven knew he had a gift, and wanted to share it with as much of the world as he could ... girls like me, we’re the same way. Our body is our gift, and we want to share it not only with people in our immediate vicinity, but everyone, everywhere ... if you’ve got a cock, I want to know that I’m helping you get off, and if photos are the only way I can do it, then I’ll take as many photos as I can.

I don’t know where Marty got the money for it, but he’d gone out and bought dozens and dozens of costumes ... cheerleader outfits, Sailor Moon costumes, a French maid apron and skirt ... he’d even found a latex outfit that managed to be snug around both my waist and my tits - knowing my new dimension, that seemed like no easy feat.

The shoot felt like it lasted half an hour, but when I looked at the clock, I realized that it had taken us late into the night. By the time we were done, I was so wet you could have fit a whole battalion of men inside of me without effort. The last round of photographs (before the camera’s battery ran out) were the ones that I was most excited to see ... not because of the costume, which was a run-of-the-mill “sexy alien” outfit, but because I was so sure that you’d be able to look at the photos and hear me sloshing.

I begged Marty to fuck me, but my brother’s surprises weren’t over yet. He slapped my hands away from my pussy, and when I objected, threatened to tie me up.

The look on my face told Marty that it wasn’t the threat he was hoping it would be.

Reaching into the bag he’d taken from the adult store, Marty pulled out another gift to me - a collar.

“An E-cup like you,” he told me, “needs to belong to someone. And you, little sis, belong to me.”

My heart melted, and I’m not going to lie - a single tear of joy trickled down my face as Marty put it on me. I belonged. What’s more, I belonged to Marty, my older brother - the sexiest, loveliest, hottest man I’d ever known.

“You can’t let anyone see it,” he said, “especially not Mom ... but when it’s just you and me in the house, I don’t ever want to see you without it.”

I nodded solemnly - as well as the hottest thing I’d ever heard, I knew that what he’d just said was a sacred pact, and I was determined to uphold it.

“Good girl,” he said, and then gestured to his lap. “Now come here...”

* * *

We didn’t sleep much that night. Mom was out, for some reason, and so I stayed collared until we eventually got to sleep in the early hours of the morning. When he’d gestured to his lap, I’d assumed he wanted another blow-job, or perhaps even a fuck, but instead he laid me across his lap, and proceeded to spank my bare bottom.

I didn’t understand at first, but as the pain slowly turned into pleasure, it dawned on me that this was just another case of my master knowing me better than I knew myself. He knew what an E-cup needed - I’d never before had any interest in spanking, but of course until my chest had grown, I’d never had any interest in becoming my brother’s personal sex slave, or having naked photos of myself spread as far and wide as possible.

It wasn’t about me, not any more. It was about my tits.

He spanked me until tears sprang from my eyes, until I begged him to stop, until my ass was raw and red ... he only stopped, finally, when his spanking had made me cum. I tensed up, my hips thrusting uncontrollably forward, crying out in both pleasure and pain, but he didn’t stop spanking me for the entire duration of my orgasm.

Finally, as I collapsed onto my master’s lap, exhausted, he let up, and I looked up him with watery, exhausted eyes.

“Thank you,” I said, and he smiled back at me, and pulled my cock out to suck.

We stayed in that position for a while, me suckling on his penis, totally drained. It wasn’t the energetic blow-job that I’d normally give (and that my brother deserved) - it was more relaxing than that. It was almost like a form of meditation - as I sucked on him, like a baby animal at its mother’s teat, I let my mind wander and drift, and thought about my new life.

I was a slut. I was my brother’s slut ... hell, more than that. I was my brother’s property. Even as I lazily blew him, he began sorting through the pictures that we’d taken, deciding which ones to upload, which ones to sell and which ones to put online for free. A part of me wanted him to upload all of them for free, just so that as many men could jerk off while looking at me as possible, but even in my sex-crazed state, I was still capable of rational thought.

Marty deserved to make money from my body, if that was what he wanted. He could do whatever he wanted with me - if he wanted to film me being taken by a room full of men, I would have let him, just to make him happy. Not, of course, that I wouldn’t have enjoyed it... 

Finally, just as he was hitting “send” on the final picture, my energy perked up slightly, and I began giving him the full blow-job that he deserved. I knew I must look sex, in that moment - on my knees in front of my brother, my ass beginning to bruise from the spanking he’d just given me, wearing a sexy outfit and the collar that my brother had given me... 

I thought that he was close to coming, but my brother ... my master ... had even greater self-control than I’d expected. Instead of blowing his load in my mouth, he grabbed my hair and roughly pulled me off his cock, practically throwing me across the room, and standing over me with a smug look on his face.

There was fear in my eyes as I looked up at him - he could do anything to me at that moment and I wouldn’t complain. I wanted to be fucked ... no, I **needed** to be fucked, but if he’d told me to lick his boots clean, I would have done it. He had complete control over me ... and I loved it.

As my brother came toward me, I glanced down at his cock, entranced. It was so beautiful ... I wanted it inside of me. I wanted it in my ass, in my cunt, in my mouth. I wanted it between my huge tits ... but most of all, I wanted it to go wherever Marty wanted it to go.

He chose my ass, that first night. Fucking my ass when it was still sore from a spanking was a particular turn-on of his, and the soreness combined with the pleasure in such a glorious way, it soon became a favorite of mine as well.

While my brother came inside my ass that night, I glanced down at my huge, E-cup breasts. I had no idea why they’d grown so huge, so suddenly, but I’d never been so glad of anything in my life.


	Chapter 8

Saturday

I couldn’t believe it when I woke up.

I mean I literally couldn’t believe it. I stood and stared at the mirror in absolute shock. My stunned brain didn’t even notice the other changes - my hair was twice as long as it had been at the start of the week, my waist was somehow even thinner than it had been before, and in contrast, my hips had widened. My ass was plump and around, and my legs were toned, despite the fact that I wasn’t really one for exercise.

No, all that I could see was my breasts ... They’d grown.

If I had to guess, I’d say I was an F-cup, but I was in completely unknown territory here. I could have been a G, H ... do they even make “H” cup? I’d spent the first eighteen years of my life as an A, I’d never expected to have to know anything about the larger sizes.

What’s more, they seemed to be completely defying gravity. A chest as large as mine, you’d expect a bit of sag ... anything this large that stood up proudly would look fake, but somehow my breasts managed to be large, perky, and completely natural-looking.

I couldn’t understand it at all.

My brother came looking for me when I didn’t come downstairs. After filling my ass with his seed the previous night, he’d told me that he was going to cook me breakfast, and that I could wash it all down with another milkshake. He knocked on my door, and when I didn’t answer, came in to find me standing naked in front of the mirror, staring in absolute shock.

“Wow,” he said, reaching out to cop a feel of my new, huge chest. It felt incredible ... each time his fingers brushed across my nipples was like a mini-orgasm, but even when my pussy started to drip, I still didn’t move.

What now?

When Marty had first told me the Big Tits Theory, I’d understood it immediately. It made so much sense ... but he’d only explained what happened up to an E-cup. E-cups were porn stars, freaks who fucked their brothers, who got off from sleeping with anyone and everything. For some reason, I hadn’t even thought about tit-sizes larger than that ... but now, I was an I-don’t-even-know-what-cup. What did that make me?

Marty led me downstairs ... he didn’t even bother putting clothes on me. I guess that meant we were going to be fucking sooner rather than later, a thought which excited me without altering the blank look on my face.

What was I?

As I mindlessly ate the bacon and eggs that Marty served me, and sipped on the milkshake he put into my hands, he began to explain.

F-cups, G-cups, H-cups, and everything above ... they were special. Precious, he said. C-cups were a dime a dozen, D-cups were everywhere you looked (which was why he’d managed to take a different one home each night last week), and anyone could open up a browser window and find dozens, hundreds, **thousands** of E-cups, fucking and being fucked online for everyone’s amusements.

But F-cups? F-cups were incredible.

F-cups were property.

I sat there as his words washed over me. Everything he was saying made sense - he explained that F-cups had no free will, no mind of their own. F-cups exist to be fucked, to be owned; if you let an F-cup out on the streets by themselves, they’ll just latch onto the first man who glances at them sideways, the first man who shows any kind of attraction.

F-cups exist to get men off ... and literally nothing else.

And when you grew past an F-cup, that’s when you were **really** something special.

Where E-cups would say yes to anything and F-cups needed an owner to tell them what to do, G and H-cups went even beyond that. They got off on the sickest, most perverted things they could think of. They’d sit in a room for hours, just to come up with dirty things that they could do ... and their orgasms were stronger than every other cup-size put together.

When an G-cup gets aroused, Marty told me, she’ll do things that ordinary people would never dream of ... and get off on it. They’re **extraordinary** , he assured me, and then sat back to let me process what he’d just said while I finished my milkshake.

I found his words extremely comforting. I’d panicked, more than a little, not knowing what I was going to do, but as I sat there and sucked up the last of Marty’s latest delicious milkshake, I realized **exactly** what I was going to do.

I was going to embrace my life as an G-cup. H-cup? It didn’t matter. Nothing mattered, just getting fucked, getting off ... and being owned.

Marty jumped as I stood up suddenly, turning to him, grabbing him by the hands, and pulling his face toward mine.

“Come here,” I said seductively, before making out with him, letting his hands roam all over my new, hot body. His every motion sent shivers down my spine, and I swear I had a small orgasm just from him grabbing my butt.

He followed me as I marched into the bedroom ... he was curious, no doubt, as to exactly what I was going to do. I thought I sensed a hint of fear, as well, but you know what they most likely say: Nobody gets in the way of an G-cup and her perversion.

Throwing him down on the bed, I pulled his jeans off, and took his cock deep down my throat, choking slightly and slobbering all over it. His eyes opened wide in shock as I reached around behind him and put a finger up his ass, but he soon relaxed and even seemed to enjoy it.

When he was as hard as he was going to get, I sat on top of him, and slowly guided him into my pussy.

“Marty,” I purred, “I want you to put a baby inside of me...”

God, just saying the words was the hottest thing I could think of. I knew that I had more than lived up to the G-cup challenge: being knocked up by your brother was, by far, the most perverted thing I could think of, and I was getting off just at the idea of it. I imagined how swollen my tits would be, how sexy my extended stomach would look ... I’d be walking around with my brother’s incestuous spawn inside of me.

I wanted my brother to own me. I wanted to be his, in the most extreme way possible. I wanted to be owned, fucked, knocked up ... I was my brother’s property, and I wanted to be a vessel to grow his incestuous babies.

And when the image of myself being fucked in the ass while nine months pregnant came into my head, I began to orgasm, bucking and thrashing around on top of Marty’s cock, screaming his name with pleasure.

We didn’t leave the house that day, or the next. I don’t even know if Mom even came home that night, I was so engrossed by the idea of getting knocked up by Marty. As much as we both loved anal and oral, we agreed that until I was definitely pregnant, it was safest to stick to vaginal sex. I threw away the prescription that Dr Lorne had given me, thanking the stars that I’d never bothered to fill it.

Marty took me in every possible position, and we both grew extremely familiar with the sight of my swollen pussy lips being parted by his thick cock, over and over again. We only stopped to take pictures.

I swear, there are now more pictures of my cunt-lips oozing cum online than there are of my face.


	Chapter 9

Monday Morning

When Dr Lorne came into the office to find me there, a chagrined look came upon his face. I’d used a fake name, being fairly sure that he wouldn’t agree to see me if I’d known who I was. He tried to back out of the room, but when I whispered in a sultry voice that it was an emergency, his hippocratic oath had meant that he couldn’t leave, not if he wanted to still call himself a doctor.

As I’d started to strip, he’d stared at my mammoth new titties in shock. I wasn’t wearing a bra - I think I was still growing, but more than that ... I just didn’t need one. No matter how large they grew, my tits provided miles of cleavage in every top, standing firmly, proudly, advertising my slutty status.

I’m pretty sure he was starting to work out that this wasn’t a strictly professional visit, but he couldn’t walk away, and as I watched, his cock began to rise. I subconsciously licked my lips, and told him my problem.

“You see, doc, I’ve realized that it’s the role of a woman like me to get knocked up as quickly as possible. I need you to prescribe me some fertility meds - as many as you’ve got.”

“I can’t just do that,” Dr Lorne replied with a weary sigh, his eyes never leaving my enormous tits. My nipples had already begun to harden at the attention, and I saw his hand twitching, like he was having trouble stopping himself from reaching out and grabbing them. “Fertility medication can only be prescribed after you’ve been trying for months without any results...”

Standing up, I watched with satisfaction as he involuntarily moaned at the slight bounce of my tits.

“Please, doc...” I said, my huge blue eyes staring at him sadly. “You’re my only hope ... surely there’s something that you can do for me...”

There was a pause (longer than I think Dr Lorne would have liked) before he shook his head, and turned away.

“I’m sorry my dear, but there’s nothing I can do for you. Now I think ... I think you’d better go.”

I quickly moved between him and the door, and he just stared hopelessly at my tits. I took his hands and placed them on my breasts, and as his shoulders slumped, I knew that I had him - he would be putty in my hands.

I walked out of his office a few minutes later with three new prescriptions in my pocket (with the opposite effect of the last medication Dr Lorne had prescribed me) and an ass full of cum. Tempting though it was to have him fill up my cunt, I knew that if I wanted my brother to get me pregnant, he had to be the only one who could cum inside me there.

Speaking of which, it felt like it had been days since he’d last filled my cunt up with his seed - in reality it had only been a few hours, but I yearned for the feeling of his cock inside of me, filling me up with his little swimmers. After I’d gotten these prescriptions filled, it would only be a matter of time before he knocked me up - perhaps with twins, triplets ... As I drove, my hand moved my miniskirt aside, and I started slowly stroking my clit, picturing myself full of babies. I could be the new octomum, growing eight babies inside myself, expanding so quickly that I’d have to shop for new clothes each and every day ... or better, lay around the house naked, spending all my time servicing my brother and taking his cock inside my various holes.

I wanted nothing more than to be a pregnant cocksucker, a dirty knocked up anal slut ... even as I slipped a second and third finger inside my swollen cunt, I felt empty, wanting to serve my purpose as the world’s biggest slut. I’d gone eighteen years without having a baby inside of me, and in the future I never wanted to be without child for more than a few months... 


End file.
