whoopieslap 

When you fill your butthole with air, slap someone with it and a small poo comes out.

Dude if you don't shut up I'm gonna whoopieslap yo' ass

whoopieslap by ShadowNam January 11, 2011

whoopie slap 

to fill up your ass with air and slap someone with it letting out a fart in the process

shane dawson said it

dude she got whoopie slapped

whoopie slap by idonthaveapseudonym.0 January 13, 2011