Go and fetch me a shoelace or anything similar. It should be long enough to reach around your cock and balls a few times. Now fold it to find the middle. Put the middle behind your balls, and make a half knot on the base of your cock. Now run it down again, making a second half knot behind your balls. Make sure it's getting tight. Now loop it around your balls, making a half knot at the frontside. Pull it upwards a bit and run it behind your cock, making another half knot. Make it as tight as possible. Now run it down again, behind your balls and make 2 half knots.
Mmh this straining cock looks good. I think I should put that on you each time we have sex, it's got so much thicker and harder.. But that is nothing you decide about, so just leave the when and where up to me.
My that cock is all hard. Start stroking again, only using light strokes, giving the least amount of stimulation. Stroke it light and slow now. Look at me. You can't deny me anything can you? You can consider yourself very lucky having a girl like me doing such things to you. Now stroke a little harder but still slowly.
When you have calmed down from another edge which you're supposed to do right NOW without stopping stroking then you can continue. Make the strokes as slow as necessary, but don't cum. I don't have to remind you of that, do I?