It is an acronym for I Fucked Up.
John: "Man IFU."
Friend: "How did you fuck up now?"
John: "I slept with Jasmine's younger sister Jessica."
Friend: "I am going to start planning your funeral."
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Max: Iรขยยve been in the bathroom all morning after last night.
Casey: Oh you must have the D.A.D.S.
Max: What?
Casey: Day after drinking shits
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