WTF? Can you guys help me out?

I’ve just been presented an awkward request. This guy I work with wants me to hit him in the arm! He says he wants to see if he can still take a hit. He’s my friend so 1) It just doesnt seem like a good idea to hit friends and 2) it just seems weird! He promises he won’t get mad if he gets hurt but still… Its his idea to ask and let popular vote decide.

Does anyone else find this odd? Should I just do it and make him happy? If so, is this gonna turn into as bad of a deal as what I’m thinking it will?