Fucker Of MOther . This is pretty much the same as a MOFO or Mother Fucker. FOMO is more of a polite white term where the MOFO originated from niggas in the US.
A white person would say: Goddam, you are a FOMO!
A black person would say: Yo, MOFO! Wha'yo gonna do when they come fo you?
An east indian would say: Hey, Muthachode!