I have a brother that's two years older than me. He hit puberty before me obviously and was very proud of it. He always showed off by walking round our house naked when our mom wasn't home (about everyday in the summer) or in our bedroom and he would get hard and jerk off in front of me all the time. We were both on the swim team and he made fun of my penis when we would wear speedos, so I didn't get naked around him or anybody much like he did.
Eventually, though, I hit puberty too. and had the same equipment (actually bigger) that he had. I was more shy than him, but one day we got in a fight and he made me mad. I don't know why, but I thought that I could get back at him a little the next day by showing off a little ,too. Like he did. I wanted to show him that I was just as big as him if not bigger. He had stopped walking around naked so much, so I wanted to show him how it felt when your brother is naked and you aren't, too. So that morning I got up, got naked, and got my dick hard and walked out to the living room where he was watching TV. I walked past the TV (so he could see my dick good) and sat down in our recliner. He said 'what the fuck are you doing?' I said ' the same thing you do' He said 'yeah, but...whatever' SO I stayed naked for a while then got dressed. The next day, I wanted to see if my brother would get naked like he used to when he woke up. He did even though he hadn't been that much at the time. So I got up and got naked too. We both went in the kitchen and fixed cereal. We were both hard, but I started jacking off to show him I could do that too. We went out to the living room to watch TV and I kept jacking. He got up and went in our room. I thought he was pissed at me. He came back out though and stood next to me while I was sitting on the couch. He told me to stand up. I said no at first but eventually did it. He had a hand behind his back. I didn't know what he was going to do. He pulled it out and it was a bottle of lube that makes your cock tingle. He squirted some on my cock and said 'this will make it feel better.' I was shocked. He sat down on the other end of the couch and started jacking off. I sat down too and started stroking. He started asking me questions like how often I did it. He then asked me how big mine was and I told him 7 inches. He told me he didn't believe me cause his was only 6 inches when he measured it. So he told me to stand up again and we compared them sided by side. My was bigger but neither of us cared much. I think he was actually proud. While were putting our dicks next to each other we started rubbing them. I told him that his hand felt good on my dick. He said, 'yeah, yours too.' So we sat down next to each other and started stroking each others cocks. He came first all over his stomach. He put some of it in his hair and said its like something about mary. Then he kept stroking me and when I came, he pointed my dick so some of my cum would hit him. It felt a little weird afterword, but it felt good too. We started jacking off with each other about every day that summer and it actually made us closer and better friends. We even had games like who could shoot the furthest and jack off most in one day. We also had a game called sneak and shoot where you had to sneak up on the other and shoot cum on him when he wasn't expecting it. We still jack off together some, but not as much cause we both have girlfriends now and don't live together.