The Gas Face is a sex act involving two consenting adults. It involves two people in a 69 sex position with the male’s face and tongue in the girl’s asshole as she farts into his face and mouth, while he sucks the farts out of her asshole.
Jack: Hey bro, did you do The Gas Face with Ashley last night?
Darius: You betterbelieve it bro, her farts were nasty, but I enjoyed doing The Gas Face with her.
Jack: You nasty, man.