As the title suggests, I've (30 M) been having casual sex with my MIL (53 F) for a little while now.

A little info on the background of our fling. Around 3 years ago, my FIL who was genuinely an amazing father, husband, and person in general, passed away from leukemia. He fought it for 5 years before he became terminal. He was adamant in his last days that she should have fun with her life and enjoy it as much as possible, even without him.

My wife (29 F) and I have been married for 9 years. We made a decision together 4 years ago that we got married far too young, and that both of us never really got to experience sexual exploration and expirimentation besides with each other. On top of that, neither of us is really comfortable with what the other wants. However, we are still deeply in love, and could not live without each other. So, we decided mutually that we would have a VERY strict open relationship. That being: both of us are limited to 3 sexual partners a year, both spouses meet and kind of "interview" each partner, no criminals or family, and both of us have to approve of the partner before any kind of encounter is made. Honestly, I feel as if though we're nore open and honest with each other than ever before. However, I have been breaking one of those fundamental rules for the last 2 years.

It started with little compliments being thrown to one another. Keep in mind, I have ALWAYS found my MIL to be extremely attractive. She's on the taller side, 5'8, and has a wonderful milf body with massive natural tits and the most beautiful hazel eyes I've ever seen. Even though her job requires her to be in shape (pilates intstructor), I would always compliment her on how hard she works to keep in such good shape. She would always compliment me on my looks and how kind I am, and always say how lucky her daughter was to be married to me.

It all really started when one day I got a text about how my wife had told her that we were in an open relationship and what the swinger lifestyle entailed. I was a little upset, since we weren't supposed to tell our families. But, MIL was more curious than anything. She went on to explain that she had been interested in the lifestyle since her husband passed away. She eventually asked of we could talk about it over some drinks because she was too embarrassed to ask her daughter. I obliged. That dinner went well, and she actually seemed attentive and curious. She had a few drinks, but I'd been sober for 3 years at that point and didn't have any.

As I was driving her home, she starts to rub my thigh and said that she was pretty sure it was the booze talking, but she REALLY wanted fucked that night. I was still adhering to the rules my wife and I set, so I brushed it off. I dropped her off at home and thought nothing of it. A few weeks go by, we'd talked and the thigh rubbing was never brought up.

One day out of the blue she tells me to come over after work to help her move a dresser and help her build a new one she'd ordered. I show up at her house and make my way in. She's nowhere to be found, so I call for her. She yells from across the house that she's getting stuff ready and to sit at the table to form a game plan.

I'm sitting for a little while before she tells me to close my eyes for a surprise. It was my birthday in a few weeks so I'd figured she was just giving it to me early. I open my eyes and she's standing in the doorway of her kitchen soaking wet and completely naked. I didn't even try to look away or act shocked. Her amazing toned, milf body was on full display. I stared at her for probably a solid minute before she said she wanted me to get naked as well. I didn't even argue. I stripped down to nothing with my cock rock hard.

She comes over and brings me in for a deep, messy kiss with our tongues down our throats before grabbing my cock and leading me by it to her room. She sits me down on her bed before getting on her knees and licking my dick a few times before looking at me and saying that I needed to shower. She then asked me what I wanted her to be wearing when I got out. I told her that I'd fantasized about her in pantyhose without panties (my biggest kink/fetish), a skirt or dress of some kind, and high heels. She said she would gladly put them on for me. I take a 5 min shower and come out to her wearing a sexy, tight skirt, black pantyhose, a blouse, and heels.

She grabs me by my cock again and puts me on my back on her bed. She gives me the hottest and longest BJ of my life before ripping a hole in her pantyhose and sitting on my face. I eat her out for a bit, and then she moves down to my cock and rides me for maybe 30 seconds before I bust the biggest load of my life inside her.

We fuck 3 more times that day before I go home. There was no dresser lol

We've been regularly meeting up since. Sometimes she comes to my job site and we fuck in my work trailer, other times we meet up in a random parking lot and she gives me a blowjob.

I would be lying if I said the sex wasn't 1000% better than any sex with my wife. We've both vowed to keep this an absolute secret from her. It would destroy both of our relationships with her. I still love my wife more than any other woman, her mom just fucks better.

Thank you all for reading! It feels good to get this off my chest.