Iron Cock Clench

An exceedingly firm clench, hold, or grasp around the shaft of the victim's penis, that is so forceful that it is deemed 'iron'. It is painful, and commonly used for, a bargaining piece, a way of releasing anger, an action of aggression, or to see the look on their face.

"I got George in such a good Iron Cock Clench that he almost pooped himself."