I only masturbated once while not touching myself. Here is what happened.
This happened only once. When I was in 7th grade, and at my horniest, my cousin came to visit for a few days. He was a year younger than I was. I don't know why, but I wondered if he masturbated. I had learned about a year earlier, and after he was there for four or five days and I hadn't been able to do it because of lack of privacy, I was really feeling the urge. So this one night we talked in bed for a while, and fell asleep. After a while I woke to a shaking of the bed and could hear some rustling. I was on my stomach with my head facing toward my cousin, so I looked over, and sure enough, he was rubbing himself on his pillow. I got immediately turned on and popped a boner. I watched him, not wanting to disturb him, and got more and more aroused. Finally when he stiffened and shook and I knew he was coming, I did, too, right into my underwear. I hadn't touched myself or moved at all. It felt great, but when the semen cooled down it felt cold and sticky and uncomfortable, and I had to wait until he fell asleep again before I could get up and clean myself off. That was fun, but messy.