I love to masturbate. My wife and I have a friend named Jackie who is very sexual in the way she talks and acts. When she comes over to our house to use our hot tub, she wears a very small bikini. She will also sunbathe with us on the deck naked. Although she has seen us naked, I have often thought about what it would if she saw me masturbate.
One day when she was over, my wife and her went for a walk. I was sitting on the sofa that we have on our deck near the hot tub, naked except for a towel around my waist. They left and said they would be back in a while. After they left I went to the front window and waited for them to come back, all the time playing with myself to stay hard and not to lose my nerve.
Finally they came back and by the time they got to the back door I was laying on the sofa. I had my feet facing the kitchen window by the hot-tub, my towel was open and I was rubbing myself. About six feet to the side of the sofa is a set of large French doors, leading from the family room to the deck. When they came in I could see them walk past the kitchen window and saw Jackie look out the window. She saw me masturbating, but I don't think my wife noticed.
As they walked past the French doors Jackie stopped and looked right at me. I acted surprised and tried to cover up. I also stood up, but as I stood up the towel slipped and I started to cum. She smiled and told my wife I was getting my load off. I acted embarrassed and covered up, but it felt great. Nobody was mad and I made sure it happened again.