Penn and Teller

While the man and woman are having sex in the doggy style position, the man has a friend waiting in the closet who comes out, then the man pulls out and the friend enters without the woman noticing, the man then runs outside quietly and up to the bedroom window where he knocks and when his girl looks up he waves at her, thus giving the magical illusion named penn and teller.

The biggest part of this sex act is to be fucking standing up, with the girl up against a window, or, better, a sliding glass door. It involves three people; you, the window girl, and your male friend in the closet. While fucking her, "accidentally" let your dick slip out, while your friend silently pops out of the closet and takes your place. Then, sneak outside and wave to her through the glass.

It is a variation of the Houdini where unknowing to the girl you are doing doggy style, there is a short mute guy standing in the corner watching. Then when she turns around after you spit on her back and she thinks you have finished cuming, you let her have it on her face while at the same time she realizes the weird guy in the corner is watching the whole thing. This double whammy could only be called the Penn and Teller

n. a sexual act. the setup is the most important part - the female is looking toward a window. the male is penetrating the female from behind, while his buddy waits quietly in the closet. at an opportune time, the two switch seemlessly. the first male quietly walks out of the room and pops up in front of the window the unassuming female is facing. MAGIC!