You twitch and stroke, while Crystal teases you, saying:
"God! My pussy is so ready for your cum! I can't wait for you to be ready to *pop* inside me!"
You don't know how excited you have to be to have an orgasm without your wife triggering it, so you get more and more horny, more and more close to an orgasm, twitching and stroking for 10 minutes, although it feels like much longer.