When I was 15 I had a friend stay over one day. We eventually started talking about nudism, and it lead onto a fun mutual masturbation session.
When I was 15 I had my friend come over one weekend so that we could hang out. My parents were out at work, so we had the house to ourselves. After doing normal teenage boys things for a while, we started to get bored and decided to search the internet for things to do. After browsing for a while, we found a website that had some fun ideas, and one took out interest. The idea talked about doing the most daring thing you could think of without hesitation. (Basically, do the most daring thing that you would willingly do).
We talked about the idea for awhile, and James (the friend who was at my place) said that he thought that it would be a fun idea. So we cleared an area, sat down and began to talk / play our new little game, and after a while it came to my turn. I thought for a while, and said that the most daring thing I would do is to strip off and stay naked for 20 minutes. James laughed and said that I would go naked, seeing that I wasn't the type of person who talks about that sort of stuff. However, just to prove him wrong I stood up, took my shirt and pants off and within a second I was standing in front of James butt naked. James looked really shocked, but I could tell that he was having trouble keeping his eyes of my penis. I didn't have the biggest penis in the world, but I was probably just bigger then the average for my age.
James began to question me about why I was so willing to get naked, as he didn't think I would do it, but I explained to him how I was a closet nudist, and being naked was one of the best feelings I had ever felt. After a while of persuasion, I managed to get James to strip off, and not before long we were both standing in from of each other naked.
I was having a lot of fun, but I could tell James was feeling uncomfortable, and his penis was pretty hard. I told him not to worry, and to sit down and relax. As he sat down on the couch, I knelt down in front of him and began to play with this penis. He was nervous at first, but the sensation must have taken control as he began to really lay back in pleasure. His dick was around average, just a bit smaller than mine and wasn't cut, but was still quite thick. His public hair covered his crotch, and as my hands went through his pubic hair he started to pulse. I moved my hand up towards his dick and began slowly jerking him off.
Not before long, a big squirt of cum blew out of his penis, and all over my hand. After James recovered from what just happened, he began to say that he might try out nudism a little more.
After this experience we got together plenty of more times, with many more mutual masturbation experiences.