Looking back, I don't remember where the impulse came from. Perhaps it was something I had thought about before that morning. Or maybe it was just occurring to me now, for the first time. Whatever the case, as soon as the thought crept into my head, it completely took over, and I couldn't think of anything else. I lay there debating with myself for a few minutes, unsure if I wanted to proceed. Then, slowly, I reached my left hand under the sheet covering us. I slid it down the front of my t-shirt, reaching the bulge in my tightey whiteys.
I let it lay there for a moment, feeling it's weight and heat on my straining hard-on. Then, I gently slid under the waistband and wrapped a tight fist around my cock. I lifted up, my hand and cock emerging from beneath my underwear, but still concealed by the sheet. I know jerking off in front of one's partner isn't necessarily that high up on the kink scale. But it was something I had never done before, and it was a rush. I was nervous, my stomach filled with butterflies. Doing this while she was asleep was the only way I could work up the courage, but the excitement came in knowing that she would be awake soon, that she would catching me playing with myself right next to her.
The pleasure was agonizing as my hand slid up and down the length of my shaft. Doing it with my left hand (I'm right-handed) seemed to add a little extra something, a slightly different physical sensation to go along with the completely new mental sensation I was experiencing.