On May 3, I set to try the “do nothing” method. I lay on my back with knees up, and waited for whatever sensations might visit.
Doing nothing wasn't strenuous, but the minimal effort still got to me. My legs fatigued, so I stretched out and lay flat.
An odd, tiny tickle occurred somewhere in my abdomen. I didn't think anything of it, but it was intruding on my focus. Just to make it go away, I rotated my hips backward, raising my lower back a little off the bed. I held there for a second until the tickle dissipated, then flattened myself back out. The tickle returned, so I rotated my hips again, waited a moment, and flattened again. That repeated a couple more times. Then a most peculiar thing happened.
My hips kept up the slow rocking motion after I decided to stop. It was going at a frequency of about one cycle every ten seconds. I wasn't making it happen, but it was still happening. Of course, I could have made it stop, but I chose not to, mostly because things started feeling pretty good. The familiar tingle of early-stage orgasm had sneaked up on me, and it was growing. After a few more pumps, my pelvis spazzed and drove my cock upward, just like when a girl's on top and I'm thrusting it into her all the way to the hilt.
Holy hell! That was an orgasm!