True story…….
Me and my long term partner had the day to ourselves, both kids staying out for the night , me off work. We decided to have a smoke and a chill in the hot tub, it was in the afternoon so we couldn’t have a skinny dip. My partner (I’ll call her N), had put her bikini in the wash so she threw on a lace black thong and a white vest top. I was already in the tub having a smoke when N got in. As she’s bobbing up and down in the bubbles I noticed her top had gone see through and could see her nipples, instantly, I started to get a twitching in my shorts. With my free hand, I started to play with my cock. All the while chatting away to N, her unaware what I was doing under the bubbles. I passed her the smoke and she lent over the side to grab a towel and dry her hands. Because she was half out of the tub smoking, sitting opposite me but facing away from me I had a perfect view of her arse in the little black thong. By now I was hard as fuck so had the riskiest wank I’ve had right there, no more than a meter away from her. And she didn’t have a clue. I just managed to cum as she was finishing her smoke and was still cumming as she turned back round to face me and sit back down. 1 of the riskiest wanks I’ve ever had and will be doing it again when I get the chance.
Source: reddit.com/r/eroticliterature/comments/qaatk9/hot_tub_masturbation