This is my slave's first time serving me and his cock has been rock hard the entire time I've played with him. He wants to cum desperately but I want to make it a challenge. I take a spiked cock ring and screw it down onto his cock. I tell him that for every few strokes that he doesn't cum, I will continue to screw them in tighter and tighter. I laugh and tease him as his erection grows harder but he can't cum with the sharp metal points digging into his flesh. Finally, he begs to be denied. but his cock is still at full mast!