Variant spelling of HPOA, an acronym for Hot Piece Of Ass. Made popular by a girl with a white dry erase board.
Origin dates back to Mid 2010. A prank on the internet.
Bastard: Yeah that's Jenny my assistant. A real HOPA! *wink wink*
Voice: Uh.. I think you mean HPOA asshole.
Bastard: Yeah that's what i said, dickhead!