When someone sits on their hand until it goes numb, while masturbating with the other hand. While masturbating with the hand that is already numb, the person sits on their opposite hand, so that they never have to spank the monkey with a fully-functioning extremity.
Dude. Every time I tried pulling the Stranger on myself, the feeling would come back. I ended up trying the Stranger and a Friend. It solved my little problem.