dirty schoolbus 

When during anal intercourse you urinate inside of your partner. Yellow and brown like a dirty schoolbus.

She was totally pissed when I gave her the dirty schoolbus.

dirty schoolbus by Mogged March 9, 2008

Dirty Schoolbus 

When a guy shoves a twinkie up a girl's asshole and then ejaculates on it. Afterwards, he gets another girl to eat the twinkie out of the other girl's asshole while on a schoolbus. The girl with the twinkie up her asshole then proceeds to finger her asshole and then eat the sperm and twinkie from her fingers.

Example:

Kid: Wanna get a dirty schoolbus?
Girl with tight asshole: Hell yeah! I love twinkies up my asshole!

Dirty Schoolbus by Average Kid December 8, 2016

dirty schoolboy 

sexual act. related to the shocker. While in the doggy style position you stick your thumb in the anus of your partner and apply downward pressure in order to feel the curvature of your penis inside her.

I gave that hoe the dirty schoolboy and she loved it.

dirty schoolboy by the dirty little schoolboy October 13, 2011