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."
A small, egotistical person of the male persuasion, named Christopher. Generally believes he is the best, simply amazing - the pinnacle of human perfection.
Except, he isn't.
"What's upwith you dude?"
"Oh nothing, just my bro being his usual self"
"Ahh, he being a right Twatopher again?"
"Yup!"