to flip [a coin] with someone to determine the posession of something or the right to do something. Maybe it's yours; maybe it's mine. I'll flip you for it.
1. To determine who gets to have something or do something by flipping a coin: Both of us wanted the last slice of pie, so we flipped for it.
2. To react enthusiastically or passionately to someone or something: I flipped for the new bartender. Sunbathers will flip for these new stylish swimsuits.