Setting: evening, a weekend retreat for polyamorous people, at a clothes-optional resort.
Fully dressed at first, having been to several talks, I found myself seated by the illuminated outdoor swimming pool, talking with an attractive, short-haired, curvaceous lady in her mid-fifties. (I was 42.) After a while, she said, “I should mention that I don't have sex with men I've just met, but… Would you like to play in the pool?”
I wasn't sure what that meant, but I agreed. She stood and dropped her dress, revealing a one-piece swimsuit over her luscious body. I hadn't brought a swimsuit (and I think she knew that), but when in Rome…
I rather hurriedly stripped off everything (she seemed to enjoy watching this process), then got in the pool with her.
She started dancing in the water, which was up to her shoulders. She would move in, rub her clothed body against my naked body, then spin away, move back in, and repeat. At times, she circled me and came in from behind, rubbing her hands over my naked back and hips, hugging me from behind with her hands touching my nipples, and then spinning out again.
It was tantalizing to be naked myself but to have her own body neither bare nor in reach. She was clearly enjoying the difference in our levels of exposure.
The one time I tried to hug her, from the front, she laughed as soon as my bare cock touched her suit, wagged her finger, and spun away again.
After a few minutes of this, I was so hot / bothered and hard that I was about to cum into the pool water. (Per retreat rules, a no-no: No public ejaculations.) I told her that we had better stop, and she agreed.
She hugged me lightly again (entirely above the waist), then pulled herself out of the pool using the aluminum ladder. I did the same, but for me, that meant coming out of the water stark naked with a boner pointing at the sky… surrounded by men and women mostly dressed in evening outdoor casual. (There were a few others, mostly men, who were nude, but not many.) Of the few who were naked, I was the only one in view with an erection. A lot of the ones who were dressed weren't shy about looking. Definitely a new experience for me.
I hadn't brought a towel, either, and I was kind of enjoying the embarrassment and exposure… plus, I don't have issues with how I look au naturel, so I just slipped on my sandals, picked up my clothes in one hand, and walked back to my cabin that way, my boner in full view and stable the whole way.
The path back to the cabins was lit by Tiki torches, and on the way, I passed many fully dressed people of both sexes. No one said anything, but one young woman in a tank top and cutoff jeans smiled and puckered up in a kiss as we passed. What fun!