The "Motorcycle Grip" is achieved by placing your thumb in the anus of a willing recipient (male or female...whatever turns you on), curling your fingers as if gripping your hand around motorcycle handles, and moving your thumb back and forth while making the sound of a motorcycle (I.E., Vroom Vroom, Screeeeech, or rrrrrng rrrrrng). If you find yourself able to perform this simultaneously on two willing participants then you are now performing the American Chopper.

When some little bitchboy is acting like a little tiny pee pee poo poo baby and messing up the group plans.