one who "boro's" his head into another's snitch until said person explodes in glee. Afterwards, the one that has just given stands up and the one that has just received asks, "May I give you a humdinger?" And the person says, "Are you willing?"
I'll never forget that night I performed a textbook "willingboro". After I boro'ed the crap out of her, she was willing to give me a humdinger.