I'm a mother-father-gentleman
A well-mannered and considerate man with high standards of proper behavior — ironically complete opposite to what he is showing up on the video, where he’s being rude and vaguely violent to a number of beautiful young women in skimpy outfits. He causes them to trip or fall, or rips off their bikini tops. He farts in the face of one.
Psy is probably poking fun at Korean accents as when most Koreans say motherfucking, because of the accent, it sounds like (and they understand it) to be mother-father. Here is an example:
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