The act of making a "raspberry" sound with one's mouth, while it is between a pair of labia. The vaginal equivalent of the "motorboat".
"Her baloney flaps were so large, I couldn't help planting my face in there and doin' the twatcopter." or "It's a lot harder to pull off a resonant twatcopter if she's got a 70's porno bush."
by WordTournament May 04, 2009