The Pooper is a game that everyone is playing. The main objective of the game is to not poop your pants. If you fail to resist the urge to use the bathroom in your pants, then you have lost the pooper and need to announce to everyone "I have lost the pooper".
friend 1:"I was with Jessica last night when I lost the pooper. worst moment in my life. The cleanup was horrible!"
friend 2:"dang that sucks, I hope I never lose the pooper around my friends :("
friend 1:"dude... I just lost the pooper >.<"