When a guy takes his hard dick, after having anal sex and swings it as hard as he can, hitting a person (hopefully a girl) on her cheek with his penis. If done correctly it will leave a mushroom imprint for several minutes with a lasting red spot afterwards and a nice brown mushroom stain.

the art of remembering an arousing occurrence or some porn you watched while masturbating, often handy if you have no porn or your in the shower