Mmmm... very good.
I bet you'd just love for me to take over for you... stroke you while you wrap your hands around these... wouldn't you? You'd just love to lick and suck my nipples while I stroke you off.
Well, you can imagine that while you give me 50 steady strokes up and down. This time, no stopping unless you are absolutely going to cum. But if you stop, then you have to leave and not touch that cock until tomorrow.
If you can make it for 50 strokes without stopping or cumming, you may continue.