Let me stop in my tracks

The phrase you say when somebody behind you is doing the fappy face and you are about to "stop in your tracks" and elbow them in the nose.

Bryant's natural reaction to the Fappy Face.

Joe: "Hey Bryant, fresh cakes! Michael is doing the fappy face right behind you!"
Bryant; "Is that right Joseph? Then I guess you should... let me stop in my tracks! *thrusts arm back and hits Michael in the face*
Michael: Not now Bryant...