My wife and I live in Japan and we never went to an onsen before, but she decided we could go to a ryokan for a Christmas gift for me. After some research we picked one that had separate baths (there were some nearby with mixed bathing) and also a paid private bath. Well, the trip finally came.
First, onsens are wonderful, highly recommend. But we got a reservation for the private onsen at 9 pm. We went in and took off our clothes and showered and everything. When we got in, it was super relaxing and intimate. We talked for a while, then started making out and I sucked her breasts and we were getting really into it. Finally I told her to wait up on the ledge and ate her out. Soon after, I put it in and we fucked for a while. I’m not sure if we could be heard. I tried to have her keep it down and I think we were fine, but there’s a 50/50 chance the other side of the wall was either the pump and filtration system or the women’s onsen. I’m not positive which. Anyway, I finished in her, then we washed off again and finished our time. It was amazing. Highly recommend.