Assphemy 

A fart that smells so bad, it is unforgivable.

Person 1: (fart)
Person 2: Dude!?
Person 3: Come on man! That was straight up ASSPHEMY!

Assphemy by Laturna Noes August 30, 2013

Assphemy 

irreverent or blasphemous behavior toward the ass of another; speaking poorly of another's gluteus

A:"That girl has no ass. I wouldn't want to tap that." B:"No way man, that's assphemy. She's got some cakes."

Assphemy by mattandalbc January 7, 2011