it stands for "mother and fathers (of the) italian association
the biggest association in the mob which a lot of people think is cool because they have no one else to idolize even though the mobsters commit horrible crimes.
It now can be used as a synonym for the mob, because you don't even have to be italian to say you're part of a mafia.
I am in the mafia...don't cross me or you'll wake up in your bed in a huge puddle of blood and a horses head that was chopped off.
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