Definitions by Crank Johnson
Crimson Mushroom
A "Crimson Mushroom" is given to an unsuspecting person by removing one's flaccid penis from one's trousers and slapping said penis across the cheek, forehead, eye socket or other impressionable area of the body (preferably the face) so as to cause a large, red, mushroom shaped outline on the recipient.
Crimson Mushroom by Crank Johnson August 12, 2008