I am using a combination of two different AIs.
I heard that
Claude.ai the best for writing prose, so I started using it. I think it writes very well. I use Claude Sonnet 4.6 for the non-nsfw parts, like setting the scene, describing the characters, describing locations, things like that.
Of course Claude will not write sex scenes. For some things it quite censored and will shut down when asked to write something unsuitable. For the sex scenes I use
Venice.ai. I love Venice! Everything is only stored in your browser, so there is maximum privacy. Nothing is stored on their servers. Venice has many LLM models to choose from, and some of them are totally uncensored. You would not believe the stuff I have got it to write. Bestiality etc. I have had the best success with the LLM model Z GLM 4.6. Also Venice Uncensored 1.2 works well, but the style can get a flowery and repetitive.
Venice has a Reddit support thread moderated by Venice employees.
I generate the start of the chapter in Claude, copy the Claude text into the Venice prompt box and write "Continue the story from here. Describe how she pulls down his pants and starts to suck his cock. Add some sexy dialogue in the same style as above." or whatever. Venice GLM 4.6 then continues the story with erotica while sounding like Claude.
The AI text is far from perfect. Sometimes it misses the context, omits details or uses the same phrases again and again. A key part of my process converting the story to audio with a text to speech app called
Speechify. I listen to my story again and again, and edit it until it flows and sounds right. I have lots of ideas while I working on the story, and I revise the text multiple times.
A few months ago I published an original story of over 132,400 words on
Archive Of Our Own, or AO3 for short. I wanted more stories out there like the ones I like to read, so I decided to write one. I am not going to link to it here, as it might be even too steamy even for this forum. With a little detective work you might find it.
For me it is more about enjoying the story than the process of writing. The story is entirely my own. I think of the characters, the setting, the story line, the plot (such as it is

and the events, blow by blow, paragraph by paragraph. Writing like this is a very creative process as nothing happens in this story that has been suggested by AI. It is 100% my story. Writing using AI is not as easy as some people think. Entering a prompt for a whole story will not produce anything people will want to read.
I use the paid versions of Claude and Venice. I was using the free versions and that worked well, but as I got serious about writing I was hitting token limits per day. The paid version of Venice can also generate uncensored images, up to point.
I also use the paid version of Speechify. It's expensive but the paid version has such cute and seductive female voices
I am currently working on a new story. The chat bots are my writing buddies. We have a lot of fun.