Shuttercup
Similar to the "Buttercup" only better. The act of cupping your hand, pressing it against your asshole, and farting directly into it, only you accidently shit a little bit too, then you press and open your hand against someone's face...preferably an enemy... cause after this, they will fucking hate you.
"So I'm working in my cubicle when this fuckin prick co-worker comes by and farts directly behind me. I had to get him back. After eating a burrito and pounding some coffee I snuck up behind him to give him a buttercup, only I accidently shit a little bit in my hand. I had to still go through with it. I pressed my cupped hand against his face and opened it releasing the gas and spackle filled present. I totally gave that bitch the Shuttercup!"