The day before Christmas

The day before Christmas 2023, I'd a contract to finish before the new year. Held up by late arrival of materials, I'd to stay home while my wife and 2 children visited her father and his new wife. I was getting on top the work I had to finish, had all the materials required 2 more days and it would be all done. My mother-in-law 53 dropped by as she was lonely, I thought with her only child visiting her ex-husband with her only grandchildren. So, I was all that was left of her close family. She is the pillar of the community type, goes to church every Sunday unless she was dying and maybe still attend anyway. I planned to have Christmas day off, as it would sit right with the holey joes who lived where I was working. I ordered in takeout as my mother-in-law was staying awhile and she had a couple of drinks to wash down the meal. Not a drinker as that was the first time, I saw her drink alcohol. After I cleared away everything, my mother-in-law asked me to fuck her. Saying I was the only one in the whole town she could trust to keep it a secret. I was shocked at first but also a bit horny mainly due to work so hard to catch up on the contract work. My mother-in-law is a gorgeous looking woman an older version of my wife. While I process her request my cock thought a great idea and went rock hard. I'd a few drinks also and maybe that relaxed my reasoning somewhat. But a fuck is a fuck, and I was keeping in the family. So, she stayed the night with me after having fucked her twice. In the morning, I fucked her again, couldn't blame alcohol as we were almost fully sober. Of course, we'd sex every chance we got till my wife and children got back. My mother-in-law wanted regular sex from me even after my family returned. I would get call over to fix a small problem at her place and when my wife had something else on as well. My wife noticed a change in her mother's behavior and put it down to the change of life. Reading about it on the internet she saw that some women go strange due lack of hormones and lack of sex could be a major factor also. Leading to early onset dementia it said, but no other information was given to boost their claim. I told my wife you take the internet with a grain of salt, unless you see supporting evidence. My wife was very concerned over her mother health told me; we should find her mother a man. Where was what I asked in return, as your mother puts her social position above almost anything else. Her daughter and grandchildren the only exceptions, maybe me but that might be stretching too far. My wife started looking and found no one suitable available. In May my wife told there was only one person nobody would suspect of having an affair with her mother. I asked who the lucky guy then, you was her response. Adding we'd to bed her mother for her health, I said you ask her and if she agrees I'll be happy to assist you and her with that. But you ask her. making out I thought her mother would never agree. I dropped by and saw her mother telling her of her daughter's idea. Her response was great idea that, I hope she does ask me, and I'll agree after some hesitation. No more hiding our relationship she added. I decide to add my 2cents worth, saying ask her to make it a threesome. Never thought my wife would actually ask her mother to have sex with me. I was wrong, but it took several weeks before she did. As request her mother asked for threesome sex. Then I'd to think about it, not really, I'd already agreed my wife pointed out. Reluctantly (not really) I had sex with both my wife and her mother at the same time. One problem came from that however, my wife had neglected her precautions and got pregnant. The only other change was we now all live together awaiting the arrival of our second daughter.