Fachi
Fachi is the Italian word for face. It means your whole being, but not your butt. Your butt is the anti-fachi, and it's totally separate.
"You're a total fachi, but your butt is the anti-fachi."
"I'm not a fachi. I'm just a fachi with no butt."
"He's got the fachi of a thousand men, but his butt is weak."