I was 19 and my cousin was 17 . We shared a bed while I was visiting their house. My cousin was very good looking and handsome. I had lots of fantasies about him. But never got a real chance. That day we talked about our penis size. I told him ' I have a huge one'. He exclaimed 'Really', and told me that he was unsure about his size as he had never seen an adult penis except his own and so he couldn't compare. I offered to show my cock to him, he seemed a bit hesitant. I could tell he was curious, but out of nowhere he reached over and touched it through my pants. He kept saying things about how big he thought it was, and so on.
Then he told me ' let me sleep now'. He put out the light and closed his eyes. Soon I could hear his breathing getting heavier. I thought he was sleeping. I started touching his penis through his underpants. It was soft and small. I unzipped his pants and held it in my hand. Then I started rubbing it with my hand. Soon I felt it getting harder. I was amazed, how a sleeping boy's penis could respond. I continued to move my hand slowly up and down. Soon it reached it's full size. Not a bad size, almost five inches I guessed. I was rubbing him nonstop.
After five minutes I could hear his breathing getting quicker, and soon he ejaculated. I felt his cum in my hand, and he said 'It's great!!' I was astonished. He smiled and told me was enjoying my hand's performance. Then he wanted to touch mine. I agreed. My penis was not erect that time. He touched it and said ' It's not as big as you claimed.' I smiled and answered, 'Give me a handjob I'll show you it's real size'. He started and soon it began to grow longer, thicker and harder. He felt it's size and shouted ' OH!its really a big one, let me see it. Then he switced on the light. My penis was blackish with huge, dark pubic hairs around it. He was impressed when he saw it. Then he kept his hand job going and after 15 minutes I ejaculated.
We did have a lot of fun after that. We did it in various styles. One of my favourite styles was to masturbate, getting our two penises together. He would remain lying on the bed spreading his two legs and I would sit between his legs and that way we got our penises together. Though his penis was a bit smaller than mine, it was great to feel two penises and four balls together in our hands.