Widowed Sister-in-law

It started with a simple request by my wife, find her widowed sister a boyfriend/lover. I'm 43 and my wife the younger of two is 41. Her sister 45 and has two children 12 and 10 both boys and so doesn't date at all. Luckily, she lives next to us, and my wife watches her nephew while their mother is working. Finding a boyfriend for my sister-in-law, I didn't know where to start all the males I know are either married, gay or assholes. I told my wife that and she simply said if you can't find anyone, you'll will have to fuck her yourself. Being a lifelong smartass, I replied okay when do you think she wants to join us in bed and waited for her reaction. To my great surprise and somewhat shock, she replied tonight will do, I think. At first, I thought she had seen my reply for what it was and was playing along. She wasn't our children and her sister's boys were staying at their grandparents for the weekend and would be picked up after school that afternoon. I went to work soon after our talk and gave it no further thought. I got home from work my wife and her sister were in the kitchen and I was told we were having a special meal before starting. A first I it didn't register what they were on about, when it did, I thought they were joking around with me. They weren't and I finally realized that when they both appeared totally naked in front of me, no chance they were still joking then. after a somewhat awkward start we had a threesome, and I was used by both till Sunday afternoon and the children's return. I happy to see the children as I needed a rest. So, I'm my sister-in-law's lover with the approval of my wife. The three of us get together for a threesome at least once a month, or just have one on one sex in between. I really like the arrangement now. But as they say nothing stays the same forever, I got promoted and with that I decided to get a bigger house as our house was a bit small for 2 adults and 4 children. Of course, my wife agreed we needed a bigger house as there was no room to enlarge out home but didn't want to move away from her sister. But she found a house that suited our needs, bigger than I was thinking. But to my wife and sister-in-law perfect for our needs, we put our house up for sale and my sister-in-law likewise put hers on the market. She and her boys live with me my wife and children in the new house, our bedrooms are linked by a shared bathroom. So, our love life could continue as before only more often. It is working great for us, and the new house is still in the same area as our previous houses, so no change of schools was required, and the children still have the same friends.