At the time I was 15 and my cousin was 16.
My cousin and I are good friends and used to talk and joke about jacking off when we were younger but it never became anything until one night at a sleepover at his house. He suggested playing a game of strip poker and I told him that I was down for it.
The game went on until we were both in our underwear and I asked him "what should we do now?" and he told me that since we had gone this far, we might as well take off our underwear too. At this point, both of our dicks were insanely hard and he had a ton of precum running out of his tip.
We sat down beside each other and started jerking off a bit, and we were both admiring each others' equipment. I thought his dick was really cool because he was uncut and I wasn't. (For the record I'm about 6 1/2 inches, cut and straight, and he's about 5 1/2, uncut and curved.) Then he said "do you want to try stroking mine?" and I told him that I was okay with it as long as he stroked me as well. So we jacked each other off for awhile.
Then I said "have you ever wondered what it would be like to get a blowjob?" and he asked if I wanted to try it. I said yeah, so we sucked on each other's dicks for a bit. Then he said he wanted to try something, so he made me lie on my back and we got into a 69 position. I had my hands on his ass and I slowly started moving my fingers toward his hole, then started rubbing it. He moaned and started doing the same to me.
We sucked on each other like that for about 10 minutes, and then we decided to both finish on each other. He blew his load on me and then I did on him, and we played some computer games before doing it again. A great experience, and we still jerk off together now.