doppelbang (v.): to intentionally get a girl so drunk that she has sex with you because she confuses you with her boyfriend
Michele: "Yo, how did Bill manage to fuck Molly at that kegger when her boyfriend went to the bathroom?"
Michael: "He totally doppelbanged her!"
friend 2: "um, she's looks exactly like you."
friend 1: "what's wrong with that?"
friend 2: "it just means that you're a total doppelbanger, that's all."