I (F26) stroked an old and lonely man's penis on the beach.
Last summer I went on a solo seaside trip. Weather was perfect so I went to the beach pretty much every day. There was a nude one right next to the main beach separated only by this green mesh fence. It was way quieter, no kids and crowds, so not long before I need to go back home I went there.
Found a shady spot under trees, got naked and started reading a book. Not even 10 minutes later some random guy walks over. He was in late 60s, maybe early 70s. He joked about me hiding in the shadow when the sky is clear and says I should swim. I decline politely.
Then he randomly starts telling me his sailing stories. Asks if I sail, tells me about his youth. Seems lonely so I let him talk. But I can't help noticing he's getting hard, and at eye level and it's pretty awkward. I pat the sand next to me and he sits down immediately. Keeps chatting, asking if I live here, how often I visit nude beaches. Then he starts randomly complimenting me. Says I have beautiful skin, legs, chest, whatever. And while he's talking to me he shifts onto his side, kind of aims himself towards me. He starts twitching his penis more aggressively making sure I see how hard he got.
I look eventually and he sees me looking and smiles. I feel my face get hot, and definitely feel it down there too. I shake my head but I reach over anyway. I start stroking awkwardly, not trying to make eye contact. He stares at me the whole time, breathing heavy, looking from my eyes down to my chest and between my legs. Takes maybe 5 minutes before he tenses up, twitches and finishes on my hand and sand. He asks how long I'm staying, wants to meet again. It was my second to last day and since weather wasn't that nice the next day I just went sightseeing and the next day I left.