This story is completely true!!
Two cousins, one bed, a very hot night.
When I was 15 I was visiting my 14 year old cousin who I didn't see regularly. When I got to his house we had some pizza and then went up to his room. We were talking about girls and school and got on to the topic of masturbation, I asked him if he jacked off, and he said no, I was shocked then he said do you and I said yeah of course! He replied saying "oh is it good?" And I said "hell yeah it feels awesome" then to my surprise he said "can you teach me?" I was shocked but said "sure" so he climbed on top of his bed and so did I....
As it was a hot summers day we were both only wearing shorts and underwear, I sat up on the bed and slid down my shorts and sat in my boxers, looked at me and said "should I take mine off?" I said "yeah we can compare cocks first. " so he quickly pulled off his shorts and was in his boxers, I could already see the outline of his hard cock. I took off my boxers first revealing my large and now very hard 8" to him he looked in amazement. I said "ok your turn dude" and he slipped off his boxers and to my surprise he had quite a big cock at least 6" he said "what next then" and I said "ok lie down and watch what I do then when you get it join in."
I started to stroke my hard cock I could feel it bulging in my hand. I started slow and then built up the speed. I looked over and could see my cousin had now started to jerk himself too. He was good, for a beginner. He said "is this ok?" And I said "yeah, perfect, you already look like a pro" he just smiled and looked at me pumping my cock. We were both pumping in sync and I said "you like it?" He just nodded and made a groan. I carried on pumping hard it was so hot and is both squashed up on his single bed made it even hotter. I said to him "watch this, I'm about to blow" I pumped fast and hard, I felt my toes curl.