His biology professor, and she's not happy

Aaron's head is spinning as he emerges from the cafeteria onto the campus footpath outside. Professor Hamilton, his biology professor, is waddling awkwardly from the bike shed, rubbing her rear. She's red in the face, and doesn't look impressed.

"Good morning, Mister Shaw." She grumbles, audibly in a bad mood.

"Morning Professor. Are you okay?" Aaron replies, not even thinking, because he's too distracted still being shocked by what he just witnessed Beverley do.

He immediately regrets asking.

"I'm furious, thanks for asking." Professor Hamilton grumbles. "There's a serious design issue with my new dress. See if you can work out what it is."

And then she turns round, and grabs her huge bottom through her skirt, revealing... A hole in the dress directly beneath her tight pink asshole, with an anal sphincter which looks very puffy and well-used.

"Oh my god." Aaron exclaims, horrified.

"Oh my god is right." Professor Hamilton replied grimly. "It's a fucking outrage."

"Why... Why would that hole..." Aaron says, gulping.

"Why would it be so small!" The professor finishes his sentence for him, but not in the way that he expected. "My SaddleShaft 5000 has a 3 inch knot at the base, and this hole is like 1.5 inches wide at most. There's just no way to get this knot through this dress and up inside me to properly secure me to my bicycle saddle!"

"Secure you... To your..." Aaron begins to ask in confusion, before he spies a classmate, Davina McCall, dismounting her bicycle outside the shed.

With a loud 'pop', her asshole pulls up and off the huge bulbous knot at the base of this black, chunky dildo protruding from her bike saddle. Her trousers split at the back, revealing lacy assless underwear, and providing unrestricted access to this most delicate and private of locations.

"What the hell is going on..." Aaron asks the universe weakly.