German Bobsled

While following someone down the stairs, let them get ahead of you a bit. Position yourself sitting at the top stair, yell "EINS, ZWEI, DREI", and lunge yourself at them crotch first and spread eagle with the speed of an Olympic bobsledder! If you're lucky, your intended will grab you by the crotch in an effort to slow your descent.

Dude, last night I was showing someone around my apt, and I got surprise German Bobsledded! So naturally, I totally reciprocated with the crotch stop

1👍 1👎