Mother in Law

I'm David 27 married to Linda and we have 2 children and I'm a work at home accountant. I have a home office as we live in a small town and have a large house. So no need for an office. Last year Linda's Mother Grace and Father divorced and she moved in with us. Grace 46 great looking body and face except for the sour look she always has. The ex husband Kevin said That she can turn fresh milk sour, just by looking at it. In the years that I've known her I have never seen her smile. Anyway Linda and the children went to visit her brother Kevin jr and his family for a holiday. I couldn't go because in was Tax time my busy period of the year. Grace didn't go because Kevin sr lived with Kevin jr and family. So I was left with grace, I consoled myself it was only 2 weeks. On the third night alone in the house together I was sitting on the porch having a couple of beers in the cool night air, when Grace came out and joined me drinking wine, as she did often. She would drink wine everyday, she got it by the case. After a bit of time she started to whine about her life. I having had a few, finally said If got rid of that sour look on your face and stop whining, you might start to enjoy life a bit more. She stopped whining and glared at me for a moment and then said You don't know my problems. I replied saying If you weren't so frigid and had a good fuck once in a while you would be a lot happie. She stormed inside saying Your taking Kevin's side as all men do. I sat on the porch finishing the beers before going inside. After locking up downstairs I headed upstairs to go to bed. As I passed Grace's room I heard crying inside, feeling a bit guilty for what I had said. I went in to console her and apologize, I sat on the bed beside her and tried to apologize. But I didn't seem to be getting any where, as I stood to leave, she turned over and said Do you think I'm frigid. Yeah I replied, with that she said How about you giving me a the good fuck as you said I needed. I was a bit taken aback at first. Then replied Okay if you really want too, she got up and started to undress and I got undressed. We both got back into her bed and had sex, When I woke in the morning next to Grace with a bit of a hangover, I got up and headed for the shower. About a hour later she came down to the kitchen were I was making breakfast. She looked at me and said Did we have sex last night or was I dreaming. I replied Yes we did, but we both had a bit to drink. With that she said So I'm only good to fuck when your drunk. I replied No I don't mean that, I mean our judgement was impaired by the drink and even if I hadn't been drinking I find you attractive, but you're my mother in law. I feel I might have taken a bit of advantage of you last night. So if I wanted you to fuck again now you would She replied. Yes, your a very good looking woman without that sour look on your face I replied. Okay then after we have breakfast you can fuck me again, or less you have something else you want to do. I've no appointments till after lunch and I'm up to date with my accounts. So we had again and she slept with every night until Linda and the children returned. Linda at once noticed the change in her mother and she asked what had happened. I said I took your suggestion that your needed a good fucking. You fucked my mother she replied, Yeah and she's not as good as you. Yet I replied. Waiting for her to get angry with me. But she said I'll go and have a talk with mom. After an hour they both came into my office and told me That tonight you've 2 women to satisfy. I don't mind you fucking my mother, as she needs it. But I won't let you fuck anyone else Linda said. So I can keep fucking Grace then I replied. Yes Linda said I'm pregnant again and mom can help keep you happy during it.