Well, here's a fictional naked in a hot tub story. There was a couple on a vacation. They had a private hot tub. One evening, they got in naked as they thought they were completely alone. But suddenly, a little squirrel showed up on the fence nearby. They were a bit embarrassed at first but then just laughed it off and continued to enjoy their time in the tub.
I don't have any real - life naked in a hot tub stories to share. But I can imagine a funny one. Maybe a group of friends decided to have a hot tub party. One of them accidentally dropped their towel outside the tub before getting in and had to run around naked looking for it while everyone was laughing.