This requires two people. One people must take their thumb and index finger, and pinch that tricep of the other person's, without them suspecting it. This usually results in a lot of pain if done correctly, and a slap in the face.
Girl 1: Man tony your such a crab ass...
Girl 2: don't be so harsh say crabby butt nipper instead so you don't sound like such a bitch
Tony: thanks , I agree that sounds better