if someone happens to be getting fresh with you, mushroom slap them. This means pulling out your jimmy and making solid contact with their facial region.
When a guy takes his hard dick, and swings it as hard as he can, hitting a person (hopefully a girl) on her body with his mushroom. If done correctly it will leave a mushroom imprint for several minutes with a lasting red spot afterwards.
A Mushroom Slap delivered with such force that; a bruise, swelling, permanent tissue damage, or even breakage to the jaw is resultant.
"My God Charlie, what happened?-are you ok?"
"Ben gave me an Intergallactic Mushroom Slap. Because he's on parole the government is footing the cosmetic surgery bill, so hopefully I'll be able to laugh about it in years to come."
Tony mushroom slapped Albert so as to awaken him from his incomprehensibly negative, drug-induced rant. (But Bert just became further enraged and had to be wheel chaired to bed.)
