In my grad year of high-school a kid named Shaun used to always go into my buddy Conor's locker, and take 1 whole bite out of everything in his lunch. (I'm talking a bite out of the sandwich, carrots, etc). Eventually my buddy just decided to jizz in his ham sandwich.. all over it... and took pictures, prior to putting in his locker.
Sure enough.. Shaun took a bite later on that day!!! hahahaha.

The funniest part was he couldn't do shit back..!! It's not like Conor did anything to Shaun personally... he just wanted to cum in his own sandwich LOL.