He shouldn't

You've heard that pinching a guy's knob really hard can stop him from cumming and so you decide to try it.

Tommy screams as you forcefully prevent him from reaching climax.

"Fuck, Joy," he says. "What are you doing?"

"No cumming unless I tell you you're allowed," you say and give him a cross look. "We're in here to wash off all the cum you sprayed all over us, not make more. Besides, I want you to learn to control yourself and not blow your load so easily. Don't worry, I'll let you cum later."

"Oh, alright," says Tommy, still looking pained. "But did you have to do that with my cock?"

"Yes," you say, "and I'll do it again until you learn to control yourself."

"Fine," Tommy says, obviously not meaning it, but somehow turned on by being under your control. "So do you want me to wash you now?"

"Yes," you say, "and you can start with my..."