The first time anyone saw me cum
My parents had told us they were going on a short getaway over a weekend and they decided to leave me in charge of the house. I was probably 15 at the time which made my brother 13. The Saturday morning when I woke up they were already gone, and my brother was already downstairs watching TV. As always, I woke up horny that day, and I decided I was going to jack off downstairs where it was cooler. Our basement was finished with the big TV and furniture, and the two of us spent a lot of our time down there.
I grabbed my laptop and a couple of tissues and went down, stripped completely naked and my penis was half-hard. My brother has seen me naked before, but never with a full-blown erection. When I walked in front of him he asked me 'what are you doing?' I sat down and turned the laptop on and told him 'gonna beat off'. 'Do it upstairs!' 'No, it's too hot up there. You don't have to leave but I'm not stopping.' I pulled up some pretty hardcore porn and leaned back, my penis now rock hard. I started stroking and I glanced over and I could tell he was just staring in shock. I told him 'you know you don't have to just watch, I know you do it.' He tried to deny it but I told him I've seen his trash can and all the tissues in it. He then said OK and got up, walked out and came back with his own tissue, stripped off his shirt and shorts, then his underwear and sat by me, naked as I was. I turned it up as a woman was getting pounded by a guy who was hung like a horse and his little penis sprung up. His four incher was much smaller than my six, but he had a lot of growing time ahead of him.
He started stroking as fast as he could, and I told him to slow down because it feels better that way. He made his pace like mine, but I had been at it at least five minutes longer and I felt my orgasm starting to build. I always like to stop before I cum, and if I can I go right to the edge and push as hard as I can, stopping the orgasm from coming. I did just that, and I let go and pushed, a thin stream of cum running out onto my belly, but without an orgasm. He asked me if I came, and I just grunted out no. When I could I wiped it off and stroked again, and a couple minutes later it happened again. After this one my penis felt like it was about to explode, but I kept on going. The next time I tried to stop but I couldn't help but blow my load, the first shot hitting me in the shoulder. I shouted out 'oh shit yes!' and started stroking hard and fast, the next two shots going straight up, then rolling out onto my hand. It felt like my penis was vibrating it felt so good. I was in ecstasy when I heard him say 'oh I'm gonna cum', then looked over as I saw one thin line shoot out onto his chest, him squirming around and his toes clutching air. He squealed and said it felt so good and I kind of giggled, just because of seeing my little brother masturbating.
I tried wiping up my cum but there was too much of it, so I said I was just going to go take a shower. I was halfway to the stairs and he asked me if he could come too, and I figured after that, why not? We jumped in and washed off, and afterwards we didn't even bother getting dressed. We both stayed that way for the rest of the weekend, jacking off whenever, whatever the other was doing. It went right up to the last possible second, I was laying on the couch stroking, about halfway there and he was sitting playing video games when the garage door opened. We looked at each other almost in a panic, then ran upstairs as fast as we could to throw some clothes on, my hard penis bouncing up and down with every step. I got upstairs before they came in, but I couldn't stay like that so I started stroking again on my bed, grabbing a sock to cum into. I just grabbed some pajama pants and a t-shirt, not even bothering with underwear. Luckily my penis had shriveled down by the time they saw me.
After that weekend my brother and I didn't hide our masturbation from each other, but we didn't have anything like that first time.