Ooh baby, I'm getting so turned on watching you do that. I just have to pinch my nipples. Imagining you were behind me doing it yourself, tweaking and pinching lightly.
Now it's your turn, pinch your nipples. Do it hard enough to cause you a little discomfort, but not too hard.
Start stroking slowly while you keep pinching your nipples. Make them long, slow strokes. Put on a show for me, show my how long and hard your cock is.
Have a look at the clock, and do this until it changes twice.