When you have secured his promise, gradually speed up until he tells you that he’s close. But this time, don’t stop. Instead, pay very close attention to the signs his body gives you that he’s going over the edge. File that information away for later. When he starts to cum, jerk his cock to encourage the contractions of his undoubtedly massive orgasm.
As the spurts subside, cease your stimulation of his penis and say, “Oh boy, I really coaxed a big one out of you, didn’t I? It must have made you so excited to be powerless to speed me along or to stop me when I made up my mind to make you cum. You like it when I take control of your cock!”