This happened recently. My family was out of town. I had the house to myself including the pool. Neighbors are far enough away that I figured what the heck. I got into the pool and removed my trunks. It was a great feeling.
My neighbor's daughter was back from college. Got back earlier than expected apparently and they were still out shopping.
She must have seen me and came over. I didn't see or hear her until she was a few feet away when she turned the corner of my house.
Pool is only three feet deep on the far end using the leaf catcher to try to get some stuff out of the water. As she said hi she stopped and had the oh my god he is naked look.
I turned and dropped but in a pool that small it wasn't going to cut it.
I apologized and she noted that she was shocked to see me naked. I attempted to keep myself under water but she came over to the pool.
I was getting rather hard and figured what the heck just get up and show her. Standing my dick is just at the water line. She just kept looking at it as we talked. She isn't bad looking. Petite wearing jeans and loose t-shirt. She is soft spoken and somewhat shy which made it even hotter for me. Add when you are 40 something and a 20 year old is looking at you naked its value added.
Her eyes(weak attempts not to though) were glued to my dick as we talked. I couldn't take it much more and started to slowly stroke myself. We stopped talking and she just watched. I climbed out of the pool and just started to jerk off in front of her. I shot my load and she let out a small gasp. Thankfully it wasn't one of those drippie orgasms but had a few squirts that flew some distance. She didn't flinch or miss a beat. We just stood there for a moment then she said she would see me later hopefully.