Why are you looking
here for? The joke's in your hand.
Urinal humor.

One of my favorite bully tricks in high school was to go up behind the kid at the urinal and grab them from behind and make them piss all over the place. I kind of feel bad for the janitor though. Fun times.

I saw another one where some other kid stood outside the crapper stall and pissed onto the shoes of the kids inside. I never did that... a little too demented. Proud to say that as much of an asshole as I was, I never pissed on anyone.