The OP asked for a story around the topic.
Years ago I lived in Southern CA and regularly visited a nude beach (San Onofre). One day when I was there I waded out into the water to cool off. This often caused me to get an erection for some reason. Since I was in the "family" section of the nude beach I didn't want to turn around and go back until it had subsided. Anyway, I looked over to my right side and a few feet away there was a guy standing there, boner pointing north just like mine. Moving sideways (in order to stay facing away from the beach) I casually got next to him and said, "I see you have the same problem I do." He laughed, and we started chatting on different topics, and eventually we were able to turn around and head back to the beach. During our conversation we discovered that we had a lot of common interests. Anyway, we went back to our respective blankets and that was that.
A week or two later I saw him at the beach again, so I set up next to him and we again had a good conversation. I shared with him that I was gay, he was cool with that. He shared with me that he had been married, was divorced, and now had a girlfriend, but that he'd often wondered what it would be like to be with a guy. I told him that if he ever wanted to experiment without pressure or expectation I'd be up for it (I found him very attractive). The conversation went on to other topics.
Over the course of the summer we would often see each other at the beach. One of our common interests was mountain biking, and eventually we made plans to go mountain biking on a Saturday afternoon, then go out to dinner and a movie (not a date, we were just friends) as he was free for the weekend.
So on the next Saturday afternoon we went mountain biking. We got back later than planned and were running short on time if we wanted to have dinner before the movie time. We decided to take a shower together to save time. No big deal since of course were used to seeing each other naked at the beach. We get in the shower and we're soaping each other up and of course we're both rock hard, stroking each other while soaped up. I was in front and he started to rub his cock on my asscrack, then teased my hole a bit with the head. Since he'd previously expressed his curiosity about fucking a guy, I decided to indulge him, so I reached back and guided his cock and pulled him inside me. He moaned and immediately came inside me. He was very apologetic, one for cumming inside me without warning (and he assured me that I had nothing to worry about STI-wise, and time proved this to be true), and also feeling bad that he came so quickly that it must not have been very pleasurable for me. I assured him that I was totally flattered that being inside me turned him on that much and not to worry about it, as long as he didn't infect me with anything it was totally cool.
Needless to say, we ran late anyway. We still went to dinner but skipped the movie.
We never fucked again (I think he may have been feeling some guilt since he had a girlfriend), but we did still play around on occasion. At the nude beach sometimes it was pretty deserted so I'd sit behind him with him between my legs and reach around and jack him. We would also hang out naked at each other's place and he liked when I gave him head.
Eventually I moved out of state and we lost touch. I still wonder whatever became of him. He was a great guy, very sexy to boot and I definitely would have been interested in a relationship with him, but he said he could never see himself falling in love with a guy.
P.S. - He had a gorgeous big cock, too... big on the long side, not really on the thickness side, but thick enough.