I have sex with my mother in law, Pam. I am 44 and she is 57. Her daughter, Dana, my wife is 39. Dana is a good wife, but she has lost interest in sex. She has gained a lot of weight in the last few years and doesn't feel sexy anymore, and no matter how hard I try to tell her that she is still very sexy to me, she can't come to terms with being over weight.
My mother in law moved in with us two years ago when her husband passed away. Pam is a very attractive kept woman. She is always dressed to impress and stays fit. She is about 5'5" and 115 lbs. with 38 D breasts, long dark hair and deep brown eyes.
After Pam moved in, my wife stopped having sex with me completely. The fact of her being over weight and her mother living with us was to much for her to deal with emotionally. I went for about a year with out having sex, but decided that if she wasn't going to have sex with me I would find someone else. I joined a married cheaters web site and after a couple of meetings with married women I was starting to enjoy a sex again. This went on for about six months and I had fucked four different married women. During this time I was always worried about catching a disease of something from these women and I had to worry about my wife catching me, so I decided that I had better stop before either of these happened. I had pretty much decided that I would just watch porn and masturbate to take care of my needs.
Then, one weekend that all changed. Me and Dana had planned on going shopping early Saturday morning. When we got up I wasn't feeling very well and told Dana to go with out me, she did. I went back to bed and was watching TV dozing when I heard a moaning coming from down the hall. I got up, put my robe on and went to see what it was. When I got to the living room I was froze. It was Pam sitting on the couch totally naked with one tit in one hand and in the other she had a small vibrator working on her clit. I looked over at the TV and she was watching porn, the scene was an older woman being fucked by a much younger man.
I didn't know what to do, I was pretty sure she hadn't noticed me walk up or she would have stopped, and was afraid that if I moved she would see me. As I stood there watching her please herself my cock started to get hard as it started to rise it came through my robe and was sticking out. My cock is almost eight inches long and about six inches around. I wanted to stroke it, but was still afraid to move. As I watched she had turned one of her tits up to her mouth and was sucking her own nipple, and was fucking herself with the vibrator when she started having an orgasm. As she was coming down from her orgasm she laid over on the couch, as she did I could have swore she looked right at me but if she did she didn't indicated it in anyway. She laid there for a couple of minutes slowing rubbing her pussy with long strokes when her fingers stopped at her ass hole and she started fingering it, then she put the vibrator into her ass and started fucking herself with it. This was too much I my cock about to explode and I had even touched it.
She had her eyes closed and moaning pretty loud while she was fucking her ass with the vibrator. I thought this would be my chance to move to a better location so I could watch her with out her seeing me, but as soon as I took my first step, she opened her eyes and stared right at me. At first she looked startled, but then her eyes looked down my body and when she saw my hard cock sticking out a smile came across her face. She kept on sliding the vibrator in and out of her ass and said, "I thought you were going shopping with Dana". I told her that I wasn't feeling very good and that I didn't go. She said, "you look like you would feel good to me", while staring at my hard cock sticking out of my robe.
With that, she stood up and walked over to me and wrapped her hand around my hard dick and slowly stroked it. She said, "Dana told me that you two haven't been having sex lately and I have heard you masturbating when she isn't home, so I know you still want sex; And since I don't have anyone to please me, maybe we can work something out." I didn't know what to say. She then led me to the couch by my hard cock. Before she sat me down she undid my robe and let it drop to the floor. Then she pushed me down on the couch and dropped to her knees in front of me and took my cock into her mouth.
She was an expert cocksucker, she could deep throat me like it was nothing and with no gag reflex. I was about to cum and she could tell. She stopped and looked up at me and said, "well, what do you think, wanna have some fun when Dana isn't here?" All I could say was, "yes".
She said, "well lets get this first load out of the way so you can fuck me long and good and plant the second load deep inside my pussy or ass, which ever you want." She went back down on my throbbing cock and with just a few deep throats I started cumming and she didn't miss a beat, she took all of it and swallowed it. She kept sucking after I finished cumming until I was hard again.
She climbed up on me and said, "you can eat my pussy later, right now I need that big cock deep inside my pussy.

I don't even try to have sex with Dana anymore. She has asked me why I don't try anymore, I just tell her, she will push me away so I don't even try. Pam is very understanding and is a nympho, she loves for me to cum in her mouth, pussy, and ass. We have sex at least twice a week now.