My discovery of masturbation was when I was about 9. My brother was 13. This one night our folks were gone, and my brother was in charge. He seemed awfully eager to be alone in the house, and suggested I ask my friend down the street if I could spend the night at his house. I did, not thinking anything of it.
At about 10 pm I decided to go back to my house to get another video game, and the most direct path was through the back yards. As I approached my house, I could see a light through the window of the room downstairs where we keep the computer. Out of curiosity, I walked up to the window and looked in, and got quite a surprise. The only light in the room was the computer monitor, and my brother was sitting in front of it with nothing on but boxers down around his ankles. The computer is right in front of the window, so I had a good side view. The thing that amazed me was that my brother was holding his dick in his hand, and it was hard. It looked huge to me, though it probably wasn't even 5 inches at that age. I'd seen him naked many times, but not with a boner, and it looked neat. I decided to watch.
I couldn't see what was on the screen very well, but it was obviously naked boys doing things together. But I wasn't interested in trying to see that better; I was interested in what my brother was doing.
As he used the mouse with his right hand to move from picture to picture, he was slowly rolling his foreskin back and forth over the head of his dick. I knew this felt good, since I'd done it myself many times, but with no real purpose. He did that a while, then started an up and down motion with his thumb and forefinger circling it, as though he was rubbing it. He did that for a few minutes, getting more intense and going faster, then stopped and let go. I could see his dick jerking a little, as though it had a mind of its own. He went through that cycle several times. I know now that he was doing what people call 'edging;' getting right up to the point of no return, but not quite.
Meanwhile I had pushed my shorts down and was trying to imitate what my brother was doing, and was surprised at how good it felt. I could feel some sort of tension building up. My brother was still going at it, but suddenly he pushed his feet forward and leaned back in the computer chair with his head thrown back and mouth opened. He got real tense, then stopped his hand movement and held on tight, and I was amazed to see several jets of white stuff shoot out onto his stomach and chest. I had no idea what that was or what was happening, but I just knew it was feeling really good to my brother. He just lay there like that, twitching for a minute or so, and I kept rubbing my own dick, and all of a sudden it exploded in my hand. Nothing came out, but I felt this wonderful, warm, tingly sensation, and it felt great! I was panting, and almost collapsed with the release. I stumbled away from the window still holding my dick, which kept pulsing for a minute or so.
I knew I'd better get back before my friend missed me, so I pulled up my shorts and ran back. When I got there he asked why I'd been so long, and I told him I'd had to take a wicked crap. He accepted that without question, then asked why I hadn't brought the game. I told him the truth: That I completely forgot since I was so intent on what I was doing.
We went to bed not long after that. My friend fell asleep pretty quickly, but I was still pretty wound up about what I'd seen my brother doing. I got a boner again, and decided to try to do it again, and it worked. I had another, my second, crashing orgasm. From then on I was hooked. I did it whenever I could, which was at least once a day. I also took to spying on my brother when the opportunity arose, and found that he got naked in front of the computer any time my folks weren't around and he thought I wasn't around or was asleep. I finally showed my friend, who also watched with interest, and he tried it as well like I did.
It was a great beginning!