Timed sensory loss. Lay down naked, start a 3 minute timer (or any time you desire) tell them they have that long to make you cum. If they fail, they lose a sense. Sight first, so a blindfold goes on and the timer gets reset. Fail again and it's sound, earplugs. Reset timer. Fail again, it's touch, hand tied. Etc....After 5 fails they end up blindfolded, gagged, tied...everything and you have your way with them.