Invented in Harvey, New Brunswick, Canada. A form of foreplay whereby the fist is inserted into the partner's rectum. Once fully inserted past the wrist one attempts to fully open the hand and extend all digits. When performed solo it is referred to as the Harvey High Five.
Due to an increase in medical expenses the Harvey Hand Grenade is now forbidden in all New Brunswick Prisons.
by Noisy as Dry Buggery October 03, 2010