When I was a kid, my brother, three years older than me, taught me all about masturbation. Our parents were divorced, and when mom was at work, my brother would come and go from the bathroom without covering up. He said that it was fun being naked, and for me not to tell mom of course, which I didn't. Anyway, he liked doing that, and he started to walk around the house naked. One day I saw him with a huge erection. He just grinned and said how good it felt having a boner and how he felt like jacking off. Well, I had no idea what he meant, and he said that if I would get naked too, that he would show me. So we went into his room and I undressed, and he sat on the bed and took his stiff penis in his hand and began rubbing slowly up and down on it. I got an ercetion too, and my penis was sticking up just as stiffly, so he instructed me to start rubbing it in the same fashion. We both sat there on the bed doing that, and suddenly he moaned and I saw all of this white liquid come squirting out of his dick. I was amazed. I continued to rub my erection and after another minute, I was rewarded with an orgasm, and some clear liquid came squirting out. It felt sooo good! My brother explained that when I got a little older, the liquid would turn milky like his.
Anyway, after that, my brother and began having some great masturbation sessions together. As soon as mom had left for work, we would get naked and enjoy having a boner and jacking off. Sometimes we would jack off two or three times. It wasn't long, however before we began quite successfully masturbating each other. Some times my brother would sit on top of me and squirt his semen all over my chest or on my penis. And, when he did that, he would rub my hard dick between his buns while he sat there, and it would make me come. We both were absolutely wild about doing that, obviously.
This went on quite a while before mom happened to come home early one day and caught both of us naked. And we both had an erection. Mom was surprised but not mad about it. She just said how she knew boys liked to have fun like that, and that was all. She was perfectly accepting of our shared sexual conduct and saw nothing wrong with it. After that, some mornings on the weekend, when mom was there, my brother and I would have some naked jack sessions and it was great not having to worry about gettying caught.