I fisted my mother in law

My wife's mother is a widow and we were staying at her house. I fisted her one day while we were alone

My wife and I were moving house and we had a month before we could move into our new house, we were going to stay at a hotel but my wife's mum let us at hers until we got he keys

I should say my wife and her weren't that close. We were surprised when she offered for us to stay. I guess it was more out of duty than kindness but we took her up on it and we mostly kept out of her way. We had a one year old boy so it made it easier for us to not stay in a hotel.

About a week before we were to get our keys for our new home, we got the news that there would be a delay of another two weeks. This made this happen a bit more strained but I told my wife it would soon pass. My wife was getting very stressed with the situation. I had taken a few days off to sort through some stuff and the morning before child had knocked a picture off the wall and the picture book had come out taking a little bit of plaster off the wall on the stairs. So that have me a good opportunity to fix that and do a few other jobs to keep my mother in law in the good books.

My wife was at work and my son was in nursery so I got on with filling the wall. While waiting on the filler to dry on the wall I did a few odd rounds here house. Leaky taps, loose cupboard handles. That kind of stuff.
When I went to hang the picture back up I couldn't find a hammer. There was a tool box in the garage which I was using but no hammer. Once the mother in law came back I asked if she had a hammer. She went under the stairs and appeared with one.
I said to her that I didn't think she had one, I took it off her and she smiled and leaned back against the hallway wall and said "I've got everything"
She was leaning against the wall with her eyes downcast and looked up at me once or twice.

Now I should say she is in no way sexy, she is overweight, she was late sixties and in no way attractive but shit was she flirting with me? I wasn't sure in any way. In fact I thought maybe she had said it as a joke and I had misheard her intent. I let my eyes linger on her a beat longer than usual and to be honest I was super horny as my wife and I weren't having much sex what with all the situation happening with the house.

"I'll keep that in mind" I murmured as I walked up the stairs. I hammered in the picture hook and then was really questioning what the fuck to do. It's one of those fantasies. Do the mother in law, do the daughter. See who is best.

I mean for example I walk down, say yeah I can see you've got everything and pull her in and she screams what the fuck and that's it'. No wife!!
I walk into the kitchen and say that's the picture back up, she goes up to look and I purposely don't move that much out of the way at the doorway and she brushes by me, she giggles as she walks by like a little girl and I'm fucking hard man thinking about using her.

I follow her up and she looks at the picture back up and turns and smiles, we stand looking at it for a while, neither one of us saying anything. I move closer to her, plausible deniability that I'm looking a the pic, she didn't move away but if anything she moved a little back. I moved to stand behind her and said "you've got everything?"
She giggled again and I grabbed her ass, she didn't scream, shout or anything. She didn't move as I roughly kneaded her big granny arse. I moved the palm of my hand between her cheeks and felt her crotch with my fingers. I told her to undress and I I took my cock out through my zipper. I bent her over the stairs and told her to wait. She breathed out "ok" and waited, I came back with massage oil and lathered my hands with it.
"Are you going to have sex with me" she asked "it's been so long"
"Nope" I said matter of factly, it took me about 30 seconds to have fours fingers up her cunt, her grey pussy hair was soaking with massage oil and her pungent pussy. 2mins later I had my fist up her and was alternating between hands, there was slurping sounds as I removed them and it was gaping even more as I used her. She stayed quiet as I did her apart from heavy breathing. I did this for about 30 mins and I tell you my hands were getting sore but she did orgasm in the end just my being fisted. She lay over the stairs panting and when she tried to sit round I told her to stay like that and jerked off into her loose pussy.

I see her a few times a year at family events but we never talked about it or acknowledge it. Even when we stayed for those extra weeks we never mentioned it or did anything else