This happened about 15 years ago. First a little about us. My wife and I are in our mid 50s now and we are somewhat of nudists. We live in the country and you can see our backyard from the road or vice versa. So, we are nude a lot unless we know someone is coming over. The wife’s sister is about 5 years younger than her. Her name is Jill. It was on a Monday morning I am setting on the back deck (nude) drinking my coffee. My wife has already left for work. I heard a car pull up. I thought it was the wife back again because she is always forgetting something when she leaves. So, I keep sitting there when Jill came out on the deck wanting to know if her sister was still home. It was too late to cover up and I did not have any thing cover up with. She had this look of shock on her face but kept looking at me. She asked if I was going to cover up, I said why, you have already seen me . I could see her eyes staring at my cock. She asked why I was nude on the back deck alone. I told her that her sister went to work or we both would be out here nude. She ask what I meant, told her we are nude just about all the time. I told her she that should try it sometime. She said her husband would not go for it (he is a strange man) . I asked what about you. Would you go for it? Jill smiled and said maybe. I told her to do it then. She looked at me puzzled. I said you have seen me so let me see you. She said, I don’t know. I told her, I will not tell anyone if you want to try it. She hesitated and then said, are you sure you won’t tell any one? I said it would be between only us. She then slowly took her shirt off and then her bra. She was really nervous about taking her panties and shorts off. I told her I will not look. She grinned and said, yeah right. When she dropped her shorts, I could see a big wet spot on her panties. I got brave and said, I think you like what you see form the look of your panties. She smiles and said my cock was larger than her old mans. With that she stepped out of her panties. I thanked her and told her tits were bigger than her sisters. She was naked in front of me. She said, no one has seen her naked in years. I said, well you look very nice naked. She sat in the chair across of me. She crossed her legs and I told her don’t do that because I wanted to look at her pussy which was hairy. I told her that her sister keeps hers shaved. She just nodded. As we sat there talking she saw my cock getting hard. She asked, did she do that? I said, yes any time I see a nice looking naked lady, it makes me hard. She said, we were not going to fuck. I said, fine and just started stroking my cock in front of her. She said that my cock was really big. She asked straight out if she could jerk me off. I told he, only if I get to finger her pussy. She moved her chair over by me, and started playing with my cock. I told her to put one of her legs on the arm of the chair so I could play with her pussy. Here we were playing with each other. It was feeling so good. I played with her clit then started with one finger, then 2 and finally 3 in her pussy while my thumb stroked her button. She liked this and I made her orgasm at least thre times before I had to tell er that I was going to cum. The more I exited her the more she squeezed my cock. I let out the biggest load in years. It was all over her hands, my balls and chest. She kept stroking for a few more minutes and she came again. She told me that she had never had anything like that happen to her before and didn’t even know she could cum like that. She also wanted to know if I always came with such a volume. I told her it was because of her. We sat there for a while before she said she needed to get home . She asked if we could do it again. I toll her she can come back any time she wanted and that it was just between us. She did come back for more but made me promise not to try and fuck her. She didn’t want to cheat on her husband even though he never did anything like this with her. In fact, he was not interested in sex very muck and they did it once a week if she was lucky and he seldom made her cum. She also did not want to cheat on her sister and I respected that. Her reasoning was that I put my cock in her pussy that would be cheating but we could masturbate and play with each other and that was ok. This went on for about 3 years before she split from her husband. During that time we got more bold. She asked if she could suck my cock as her husband never wanted that. I was only too eager. She learned fast and used her hands as well as her mouth. I insisted that I be able to eat her which once again she was not used to as her husband never had. She was hooked on that and we actually often 69’ed which was a buzz. For a few months after she and her husband split, I was her only outlet for sex. Then she met a nice fellow and they moved in together and have since married. When it got serious with him she told me it had to finish but thanked me for showing her what sex could be like. Her new man knew nothing about us but she said he was as good as me and also when they fucked it was amazing. I was happy for her and we never ever got caught. It was fun while it lasted but I still miss her jerking me off.