I live with one of my friends from college. Were both straight and have no problem walking around naked. He is well built with a seven inch cock, with his pubes shaved into a triangle. I'm so-so built with a six and a half inch cock. I just do the straight buzz fade on my pubes.
We've been to a couple of nude beaches before. One time when we came home he commented how some of the girls at the beach had gotten him hard and he had to hide it with his towel. I agreed. He said he was going to throw in a porn and jerk off. I asked if I could join. He said sure. He had this tube of this amazing lube that warms and tingles. My cock felt so good.
I just sat there watching him stroke his cock. He stroked his head backwards then would do long strokes on his shaft then massage his balls. They were pretty big actually. He asked if he could feel my balls. I said sure. He started to feel my sack and massage my balls. I'm one of those guys that loves to have my balls massaged and tea bagged by a girl. I then leaned over and started to feel his balls. He then went to work on my cock, rubbing the under side of my head, twisting his hand around it. It felt great.
Now I like most men, enjoy the sensation when you cum, but this was really hot. He asked if I was close to cumming, I nodded yes, he started to stroke my cock saying 'show me that cum. I'm told your a heavy cummer, let's see'. I had a reputation at college of being one of those guys that cums a lot. My cock exploded out rope after rope of cum. He was taken aback. Then it was my turn on him. I got some more lube and started stroking his cock really fast with one hand while massaging his balls with the other. After about five minutes his cock exploded with cum. Some landed on my shoulder. We both sat back relaxed for a bit and said what a great way to release from stress. We do it once or twice a week now.