When you have sex you need to do the Phantom move. Do you want me to tell what that is? Yes? Ok. Get your freak on with a banging hot chick, make sure she's on her hands and knees and can see out of the window (Make sure the curtains are open slightly for this to work). Whilst having shmecks, get a friend of your to take over for you; but try to make the transition from you to him unnoticeable. Quietly leave the room, get dressed and go outside. Once outside, climb up to your window, look into the window through the gap and wave to her. The look on her face; Priceless.