I’m trying to find a doujin I read a few years ago on nhentai, but I can’t remember the name and some of the details might be a bit fuzzy. It was English translated and I’m pretty sure it was an original work, not a parody. From what I remember, it starts with a guy and his dad talking at home, and the dad mentions he’s getting remarried soon. Later, they go to a Japanese bathhouse or onsen where the guy meets a girl, and they end up having sex. Then after/during sex, the guy’s dad and the girl’s mom walk in on them, and it’s revealed that the parents are actually the ones getting married. I’ve tried searching using keywords like onsen, hot spring, bath, marry, remarry, but nothing seems to match. If this sounds familiar to anyone, I’d really appreciate some help finding it, because it’s been living rent free in my head for like a year.