This happened a few years ago while I was renting a room from a woman who had a 3 room apartment. She had one room, I would have my own and the third room was rented by 2 other guys. For some background, It was my first time living (mostly) on my own and I was just happy to have my own space. Everyone mostly kept to themselves and didn't interact much especially since everyone had their own work schedule. The thing is one of the guys started getting home around the time I'd be getting ready for work. I wouldn't lock the door sometimes or just forget but it wouldn't matter since no one was usually home at the time. One day, though, I was in the shower with the door unlocked when that guy arrived. I didn't think anything of it since you can always hear when water is running in the bathroom and honestly I also didn't want to rush out just to lock the door. As I was scrubbing my legs I faintly heard the door open but what I heard didn't register until moments later, it had to be at least 10 seconds. I should also mention that we had glass shower doors so he had a full view of my butt. When I realized what the sound was I looked back and the door was closed almost immediately. I didn't know what to think at the time but I just thought that I really messed up by not locking the door and was just fully exposed to some random guy. I decided to not address it at all and finished my shower as normal but for the rest of the day I couldn't stop thinking about it. Mostly because I noticed that he watched me for a good few seconds until I turned to the door. To be completely honest this actually turned me on and not knowing exactly who it was made it only better. At that point I realized I really liked it and wanted it to happen again.

A few days passed without our paths crossing but I now, wanting to give him a show, intentionally didn't lock the door whenever I showered. About 4 days passed then, as I'm showering I again hear him getting home. Now I'm just waiting patiently, soaping myself up and now I'm actively listening waiting for the door to open. And it does. More quietly this time but I was anticipating it. I kept showering, facing the shower head away from the door and I could feel him watching me. This time he could watch for as long as he wanted to, I also rubbed on my butt more and bent over a bit to give him a better show. The best part came when I started hearing soft but quick breaths coming from the doorway, I never thought he'd actually start getting off to me. About 2 minutes passed of me hearing him, keeping my shower as normal as possible and trying to not turn around, then the door finally shut. I had never had something like that happen to me before and the thought of it made me feel honestly really sexy and very turned on lol. I never addressed it and ended up moving out a few weeks later when I found a better place to stay. I still think about that to this day and wonder if he'd have joined me if I invited him into the shower with me. I hope to one day have something like that happen again, it was kind of weird at first but quickly turned really hot for me honestly.