This "mother in law Fantasy" ex mother in law actually is more an ex son in law story and differs from most you'll read in two ways. One it's coming from the Mother in Law, two, it's actually true.
First, quick background. I was a fairly young mom and my ex son in law was a few years older than my daughter so the age diff is only 15, I am now 58 he is 43. She left him for another and nothing other than some flirting ever happened when they were together.
I always thought he was attractive and in great shape. From day one something was there but again, not going to happen. I had remarried an older man and sex was few and far between so yes the thoughts were there. When alone we would talk/borderline flirt. On occasion I would "accidentally" walk into a room still buttoning my blouse, bend over at just the right time etc and would catch him look and give a smile. It's all I had. Once he needed to give me a ride somewhere and he showed up with a huge hard on set a top his thigh in tight jeans, very obvious, very intentional. Anyway, recent times are what your waiting for.
She left him but we stayed close as grandchildren are involved and we live close by. My husband and I have not had sex for many years, all he wants is companionship but I need more. As neighbors my ex son in law stops by to say hi or borrow tools at times. We have talked, really he is my only confidant. He once commented how good I looked and what a lucky guy my husband is and I laughed and explained his lack of interest. His answer was what a fool he is and that if he had me he would start and end each day on top of me. Definitely the most obvious of all our flirtations. At least to that point. More recently when discussing the subject he said I needed a FWB and many guys would volunteer for the job. I said yeah more old guys like my hubby and he said no shot, told me I was bound to be more than just his older women fantasy. As he got off the couch I saw in his shorts that same hard on from that day years ago. I was about to explode.
I felt he was about to give up as he was doing all the work and I was not doing my share. I was scared. We both wanted it and trust each other completely but I was scared. He basically let me know where and when to be but I was scared. I posted for advise to a different site and although many responses were nasty, calling me names, telling me I was hell bound, that I was to be nothing more than a toy to him, most telling me as my one other friend/confidant had that I better prepare for my first anal experience, etc.. Some actually understood and where in similar binds, some offered great advice. Finally I took some. I still could not go to him, scared. What I did was call and ask if he could stop by to remove a limb from my roof. Actually a twig I tossed there. He said he could come at a time that afternoon, when he knew my husband was at work. I "forgot" he was coming and was only in my robe when he showed. He took all of 2 minutes and removed the limb/twig. When he came in I said, and this was actually my own line, thanks for coming and doing that for me otherwise I may have had to wait for a slight breeze to do so. He said he's glad I didn't wait because he had waited long enough to do this. He leaned into me and kissed me softly as he slid his hand beneath my robe and across my chest. I felt a wave of panic and my heart felt like it was pounding out of my chest. I was frozen. He stepped back a bit and removed my robe. He grabbed me by the hand and backed into my couch where he sat down and unbelted his pants. I went to my knees and removed his penis from his pants. It was beautiful, exactly how I imagined. I gently kissed and licked it then took it in, I cannot remember the last time I had a cock in my mouth. He sunk into the seat and told me he always knew I'd be awesome at this. Then he told me he dreamed of coming in my mouth but that that would have to wait for another day as he had other plans for me. He got up and laid me on the couch, removed his shirt, god he looked so good. He then assumed my prior position and began licking me. I have never felt anything that good and honestly thought he was going to make me come with his mouth. He got up and slid me up a bit, my back resting against the arm of the couch and he climbed up and slid his cock between my breasts. He then climbed higher and stuck it completely in my mouth, slowly in and out I fought the urge to choke as I did not want to dissapoint him at all. Then he lowered himself and again kissed me softly. He began rubbing the head of his cock on my clit, teasing me, I was dying! Then very slowly he went in, all the way in. He looked me in the eyes and said "finally". He fucked me better than I had ever been my entire life. I came for the first time in so long and it was amazing. He continued fucking me and I was surprised he hadn't come. I briefly thought maybe I wasn't doing it for him. Then he gave me a really good long kiss and slid out of me. He turned me over and slid me up and over the arm of the couch. O god look at that ass he said and then he rubbed and began kissing it. He kissed me right on the anus and then asked if i had ever been fucked in that sweat ass before? I said no, that I didn't do that. he laughed and said 'you do today honey"! I was nervous but no shot I was to stop him. He did, thankfully, bring a pack of lube. He put some on my butt and some on his penis and lined up. I was very nervous and then felt the head of his cock press against may rectum. God it hurt going in. He was slow and gentle but it still hurt even with the lube. Slowly he started going in and out, then faster, then he came out because he wanted to see it go in again, ouch, he then began going a bit less easy on me and faster. Grabbed me by the hair and turned my head slightly towards him. He kissed me and asked how his cock felt in my ass. I told him it felt great, that I loved feeling his cock in my ass, said he loved hearing that and then he exploded in me, he kept sliding in and out of my ass and finally pulled out and turned me over. We rested a bit and talked some. I asked if he thought I was a whore. He said, why, just because your a married women who just had her ex son in laws cock in her ass? He laughed and said yeah but it's ok so long as your my whore.
That afternoon was the best sex of my life. I have no regrets. We have repeated a couple times now and it just gets better. I know it will end soon but again, no regrets. My husband and I actually get along better now as a result. I was getting bitter and so all we did was argue. Now he has his companion, I start most weeks getting fucked by a hot younger guy, and we get along great. My whole life I did for others, finally doing for me!