A highly offensive phrase typically used to refer to individuals that have violated the G (Gansta) code, the Bro-code or any other of one of the many unspoken Man rules that exist in the U.S. and it's territories.
The word Faggot in this context is connotative of inefficiency, submission as well as an overall display of indecisiveness and feminine tendencies. Typically used to insult a man. Not necessarily used to indicate gayness in this phrase.
The word Ass here denotes moronic actions taken on part of the recipient of the insult.
The word Nigga here is a place holder or "pronoun" to refer to the individual deserving of the insult.
Marcus: Sup? Faggot Ass Nigga.
Samuel: What the fuck you coming at me like that for?
Marcus: Remember last night when you screwed up the deal? I lost $500 because of that shit! I ain't never working with cho ass again.
Samuel: I have no clue what the hell went wrong, that shit wasn't my fault.
Marcus: What you did was act like you didn't know what we came to do there last night. They saw you was shook. Now niggas think we pussy. Get the fuck out my sight I can't be associated with no Faggot Ass Negro like you.