My cock is locked in a collar that is lined with sharp metal screw tips. If I get aroused they press against my cockflesh which gets me hard which causes my cock to expand against the screwtips which causes me to get harder and harder. It doesn't take long for the pain to bring me to my knees panting in pain. Eventually I am curled up on the floor moaning in agony and begging Master to release me. All he has to say is “soft” and my cock slowly goes soft and I am so greateful for the relief. Of course I always thank him for punishing me this way.
I hope you enjoy my pain, shame, and humiliation.