A sex move: Performed with 3 people (2 men and a women) Blindfold your girl and start doing her from behind while she's facing a window, now quietly switch places with the other man and have him start doing her while you go outside and have the other man un-blindfold the girl and you wave at her from outside the window.
On a side note: She doesn't know that there are two men and that she is going to be doing two men before this move is preformed.