Back Door Time Bomb

The game of chicken you play when you're fucking a chick in the ass that has diarrhea.

Safest to play this game away from the bed you plan on sleeping in.

Burt: Oh man, I'm gonna totally bend Alana over and fuck her in the ass!
Ernie: You better be careful dude, she had Taco Bell for lunch.
Burt: Time to play a little Back Door Time Bomb