I was maybe 12 at the time. He was about 14.
Like some you, I learned about masturbation from a family member. In my case, it was my brother. This is the only time this happened, but it opened up a new world for me. Since then, I have masturbated about once a day, even though I'm married and have a regular sex life. I just love masturbation.
It all started at my grandparent's house, out on Long Island. When we visited them for the weekend, he and I would sleep on cots in the dining room. The only TV was in living room, and it was connected to an early, single channel-type cable system that showed movies. Although my grandparents kept it locked, my brother had the key, so we were able to watch adult movies late at night.
One night, we were watching a porno, based loosely on Cinderella. I was fascinated by it and as I lay on my stomach, I got hard. My brother was laying the same way next to me and I noticed him squirming. He asked me if I ever jerked off. I said no, I didn't know what it was. He said he would show me.
He went to the kitchen and got some paper towels. When he returned, he gave some to me and kept some for himself. Then, he pulled his cock out through the fly in his pajamas. His 5.5' boner stuck straight out from his body. He sat back down with his legs straight in front of him. I followed suit. As we went back to watching the movie, he started moving his hand up and down the shaft of his cock. He said, 'this is how you do it, go ahead and try.' I took my then 4.5' cock and started rubbing it the same way. It felt great. We sat there watching the movie and jerking off, but I spent most of my time watching him jerk off.
Soon he was panting and said he was going to cum. I watched, transfixed, as he held the paper towels in front of his cock and unloaded a few spurts of white stuff onto them. It was too much to watch and I got a light headed feeling and my dick spasmed. Some small globs of cum shot out of my cock onto the paper towels.
We cleaned up with the paper towels and tucking our cocks back into our pajamas. We locked up the movie box and replaced the key. I slept well that night.