Well, let's not put this mildly... the act of
masturbating whilst launching your body from an open
window.
Now, the logistics are fairly hard to pull off. You must choose a high-enough window that will allow you to have enough time in the air to achieve orgasm. Then comes the whole problem of obtaining a parachute, so you can stay on this mortal coil, and explaining to cops why you parachuted down from a high building with your zipper undone...
See the Cronenberg movie 'Crash'.