There was this another story from old forums, but a short one.
It starts in a village setting with son and mother leaving to work in the farm together in a truck of somesorts, and the first day as there were so many people the mother would sit on the sons lap and it would lead to some rubbing with the son getting excited and mom being silent about it. But on the next day the mother tries to refuse sitting with her son but gets forced by others and agrees. This time the son becomes uncontrollable and tries his luck by taking his thing out and trying to kinda insert it. As the ride ends that day, he gets a death glare from his mother and goes like that..
I only remember it being quite a realistic story despite my description and being named mother of Ametiville or something. so if anyone knows the correct name or has the story do post here