My wife and I went on vacation for five days last month. We asked my wife's sister to check on the house from time to time while we were away. We told her to help herself to our pool. She has three kids and thought they would have fun.
The day after we got home I was going through the files on my hard drive from my security camera that overlooks the yard. Most files were of my sister in law driving up and checking the house. One file was of her and her kids playing in our pool.
Another file, I almost deleted because it started off with her checking our house. After she checked the house she took off her tank top and bra. I couldn't believe I got my sexy sister in laws c cup tits on video. I got a nervous, excited feeling as my cock got rock hard.
She looked around then slid her shorts and panties down her long legs. There in front of me was my beautiful sister in law completely naked on my computer screen. As she got in the pool I could see she has a full bush. Her body is amazing. She is 5'9' and probably 135 pounds with long brown hair and a pretty face. Her boobs are great although her areolas are larger than I prefer.
As I watched her float on her back, with her amazing boobs and bush facing the sky, I pulled my cock out and stroked it. I came in just a few minutes. I cleaned up with a sock and continued to watch. Before she was done in the pool I started jerking off again. She got out of the pool and I came a second time then watched her dry off, get dressed and drive off.
I have masturbated while watching that video at least ten times. I have seen her twice since then and all I could think was 'I've seen you naked'.