Jerker's Joint

The pain in a man's arm after masturbating for an extended period of time, usually in the elbow or wrist.

Person 1: Hey, you down to help me type this essay out? It's due-
Person 2: Can't, bud. I have Jerker's Joint. I need to get some rest.
Person 1: That's disgusting. Why would you tell me that?
Person 2: *puts dominant hand on P1's shoulder* Because my arm hurts.
Person 1: Is this what I think it is?
Person 2: Yes. Yes it is.