I've masturbated to this many times, but I still wonder.
I don't remember exactly how old I was, maybe 13 or 14, but I remember this event like it happened yesterday. I can still see it in my minds eye clearly. A little background is in order first. The area I grew up in consisted mostly of old multi-family housing from the late 19th century consisting mainly of three room cold water flats. Living room, middle room, and kitchen in the back. There was a small toilet in the middle room but there was no bathtub. To take a bath you heated water on the kitchen range and poured it into a 'wash tub' usually placed in the middle room and that's where you took your bath. Our flat had a door with a glass window between the living room and the middle room. Mom had put a curtain over it for privacy when someone was bathing.
I'm the youngest of five children. Two sisters and two brothers. All of course older than I. This particular event involved my sister who is four years older than I am. I don't remember the reason for it but her and I were the only two home on one particular evening. I was in the living room and she was getting ready to take a bath. She told me to go out back in the yard while she took her bath but I had other ideas. My sister was a very attractive blonde and I wanted to see her naked! I figured if I was in the living room and she was in the middle room taking a bath I could peek through the curtain on the connecting door and see most of her body, probably from the back but whatever I would get to see something. She told me a couple of times to go out in the yard while she bathed but I told her I had a bad headache and just wanted to lay on the couch and rest. She finally agreed and I could hardly wait. I heard her pouring her bath water in the wash tub and allowed a few minutes for her to get settled in.
I carefully crept over to the door to peek through the curtain expecting to see her back but to my surprise she was sitting in the tub facing me! There they were in all their glory! Her 36B tits were staring right at me! I was in heaven. She continued to wash herself and in a few minutes she was done. How I envied that wash cloth. Sliding all over her pale alabaster skin. Then she sort of turned around, stood up and stepped out of the tub. I got a great view of her nice ass. Drying her upper body she moved to a chair she had brought in from the kitchen. Luckily for me she had placed it facing the door where I was peeking through. She turned around and sat down facing me. Now I could see the ultimate prize. Her golden brown bush (a very thick bush too) and as she dried her lower half her legs opened and I could clearly see her pussy lips! Or could I? I'm still not sure but there was some VERY white skin showing. I've thought about it for years and never have been sure whether what I saw was her pussy lips or her ass cheeks. Which ever it was I almost choked. My dick was hard as a rock and I had nowhere to go with my cum so I had to wait until she was done so I could go into the toilet and jerk off. But when I did I shot a load to be proud of.
My sister was always (and still is) very committed to her religious views so I've often wondered if she faced me on purpose. She could have easily faced the other direction while in the tub and turned the chair facing the other way for when she dried herself. I've never had the courage to ask her. I'd be too embarrassed anyway because of her religious views.