From reading the posts on this site, I see that a lot of guys discover masturbation by seeing someone else doing it. That's how it was with me.
My first introduction to masturbation was when I was ten or so. I made friends with a boy my age from school, and we had our first sleepover at his house one Saturday night. His house was a neat old farmhouse, which was the first house in the area, being the house for the farm that had been sold off for building lots. His parents had added onto the first floor, and had a master bedroom suite and other rooms down there. My friend and his older brother (about fifteen at the time, I'd guess) shared the old master bedroom upstairs.
This night his brother wasn't home. My friend had a large double bed, so we slept together. When it came time to go to bed, he undressed and, to my surprise, slid into bed in the nude. Something about that was exciting to me. I had played naked games quite a bit. Since nudity wasn't allowed in my house, any chance I got to do something naked when no one was around was a thrill for me. And now Ronny was in bed naked right next to me! I took the plunge and joined him naked under the covers. We didn't do anything sexual, but just the feeling of being naked was exciting to me, and I had a nice little boner.
Ronny and I talked for a while, and I began to doze off. All of a sudden I became aware of a movement in the bed beside me, and when I opened my eyes I was surprised to see Ronny laying on top of his pillow and thrusting his hips into it. I could tell he was enjoying it from the look on his face. His eyes were closed, but he was facing me, and he had a look of concentration.
I watched him doing that for five or ten minutes, and noticed that he sped up and was thrusting harder. The look of concentration on his face got stronger, and then he stopped and tensed, and just moved his hips slightly, pressing into the pillow. He had a look of pleasure on his face as he lay there, kind of jerking rhythmically. Then he relaxed with a sigh.
Ronny rolled off his pillow and I saw his hard little dick, all red and abused looking. His foreskin was pulled halfway back, and the head looked inflamed. He had opened his eyes and looked a little surprised to see me watching him, but didn't seem embarrassed. I know I would have been if I'd been doing something like that and discovered I'd been watched.
I simply asked Ronny what he had been doing. He said, 'Working my pillow.' Seemed like an odd thing to call that activity. Anyway, he went on to tell me that he and his brother did it every night before going to sleep. That it felt good and made him sleep better. He said his father called it 'masturbating.' I asked if his father knew he did that, and he said yes, that his father did it, too, and said they should do it whenever they wanted. I was really surprised at that.
Ronny asked if I ever did that. I said no, but I knew it felt good to play with 'that,' and pointed to my crotch. He urged me to try it, and though I was a little embarrassed, agreed. He showed me how to bunch up the pillow and lay on it, and coached me to my first orgasm. Of course I loved it and was hooked. I did it nearly every night after that.
A couple of weeks later I slept over at Ronny's again, but this time his brother was home. Ronny and I went to bed, naked of course, and were about to mount our pillows together when his brother came up to bed. He too stripped naked and got into bed. I noticed his penis was bigger than ours and had a little hair.
Ronny paid no attention to him, and mounted his pillow and started to hump it. His brother looked over and smiled, then pulled his covers down. I saw that he had a boner. It wasn't huge, but it was bigger than what Ronny and I had. He reached into the drawer of the bedside table and pulled out a tube of something, which he squirted on his penis. He began rubbing it, paying no attention to the fact that I was watching.
I felt a little embarrassed watching him like that, so decided to mount my pillow and do it too. I watched as Ronny's brother rubbed his penis and realized I was witnessing a new way to do what Ronny and I did with our pillows.
The whole scene was kind of exciting, with Ronny on one side of me enjoying his pillow, his brother in the next bed rubbing himself off, and me able to watch and get that good feeling at the same time. Ronny finished first with a heavy sigh. Then his brother finished, and I was treated to the sight of him shooting white stuff all over his stomach while he writhed in pleasure. Then I had my orgasm.
Ronny's brother cleaned up with a used pair of underwear, and we just rolled over and went to sleep, satisfied. Thinking about it, I realized that watching the two of them going at it was exciting - kind of like the forbidden fruit.
We had many sleepovers over the next couple of years, and the scene was pretty much the same. I liked using the pillow. But when Ronny and I began to ejaculate when we were 13, it got pretty messy that way so we both switched to using our hands. It was always a slightly humorous sight to see the three of us in a line, all working our penises out in the open. It was a lot of fun - fun that I wish I could have again now.