So I've been sleeping with my mother in law for about 2 years now. I'm 40. My wife is 45. Her mom is 63. Long story short, her and her husband have been sleeping in separate rooms and on separate floors for 15 years. They haven't had sex in 10 years due to him having erectile disfunction. One day I went over to pick up their tiller for my yard and she wasn't in the living room or kitchen. I called her name but she didn't answer. I went to her room and she was naked on the bed masturbating. We slept together.
So anyway, we have an agreement. Nothing like blackmail. We have sex 2-3 times a month. My wife, Jenny, obviously can never know. She'd be hella pissed. My wife thinks me and Barbara just get along really well.
This passed Christmas we were at Barb's house. We had dinner and watched TV. Every chance she got, Barb would cop a feel or a kiss. She was seriously horny. She even reached around and into my pants with my wife 5 ft away. My wife and I drove separate cars. She wanted to be there early to help cook. I work nights so I slept during the day.
Anyway, it was about 10 pm. Jenny was ready to go. Barb said, "Mind if Mark stays tonight? Jack is at his mom's house and I don't wanna be alone in this house on Christmas. Plus he's had a bit to drink and probably shouldn't drive." Jenny said, "Yeah, it's cool. A wreck would be a bad thing."
I walked jenny to her car. She gave me a big, long kiss. She grabbed my crotch and said, "Hurry back. I'll be naked when you get home." I said, "Damn tease." I walked back inside. Barb had changed into a black silk men's pajama top. Button up style. Nothing else. No panties. I hadn't even gotten in the door and Barb wrapped her arms around me, wrapped a leg around me and kissed me. She said, "See. I got you all to myself tonight. I've been so horny all day. Ready to go to bed?"