You start off fucking a girl from behind with your friend in the closet. Make sure there is a window nearby. Quickly and quietly have your friend take over while you walk outside to the window. Wave to the girl you were just fucking. Then, as the girl starts to turn around to figure out who she is having sex with, your friend donkey punches her right in the back of the head. When she wakes up, she'll be saying "whodunnit?"
One day I got really pissed at my girlfriend so I got my best friend to help out and we gave her a really hard whodunnit.
When you are doing a girl from behind, at the top of a flight of stairs, right after you cum, punch her in the face (donkey punch) and ride her down the stairs like a bobsled!
Yeah, I was doing this chick at the top of the stairs the other night, and i rode her for a nice bobsled!