Aaron woke up to a normal seeming day. He didn't realize there was anything wrong at first, his studio apartment looked the same as always, he was the same person he'd always been. Upon waking up there was no evidence of any change taking place.
Little to Aaron's knowledge however, he had been sent to a world conpleatly unlike his own in a very important way. While the change had no effect on his body, he'd soon find out not everything was the same.
Finding he had morning wood, Aaron decided to do what he normally did and jerked off. He started jerking and pulled out his phone, but the porn he saw was all of chicks with dicks. He thought it was strange so he changed to another site, but that had the same thing, nothing but girls with penises. Finally he just searched 'vagina' but found nothing, like nobody had ever heard of the body part.
As he searched it soon became clear something had changed. When he researched human anatomy he found that in the world he had just woken up in, both men and women had penises. Women were still women, they just had the same parts as men. Women conceived children analy now, and their ovaries were shaped more like testicles and were positioned in the scrotum.
He'd never interact or even see a vagina again. Aaron was trapped in a world where every women he had ever known had a dick between her legs, and only he knew anything was wrong.