What's on your mug?

It's an abbreviation for "Mother Fucker".

Guy - I fucked your mom. Dude - You sick Mo-Fo!

By kane

an abbreviation of "Mother Fucker". it is used for slang.

YOU MO FO!!!! (you mother fucker)

By Shana

slang for " Mother Fucker '

By Preston

short for mother Fucker- (a place)

someone is gonna get hurt up in this mo fo

By Gdubs

If you are a mo fo you are a mother fucker!!!!!

"You mo fo" says the boy "fuck you" you reply

By dan543