Fun in the Family

I'm married to a beautiful woman; we have 3 children. But in July 2021 she asked me would I do great big favor for her sister. Of course, I said I would without even asking what it was. Her only sibling is a lesbian, the favor was to get her pregnant. She wasn't in any relationship the time and is 2 years older than her sister and had worried her childbearing chances were running out. I was shocked at first and asked the stupid question why me, which was answered with your family and it's better to have an actual father for a child than a test tube. I still agreed as my wife was all for it, so her sister moved in with us and started sharing our bed. Which meant we had threesomes, which was great fun. I did the job as it were, my sister-in-law got along with my wife. She wasn't trying but was happy anyway, now we have 3 children, my sister-in-law has her child as well. Both new children were born Julu this year a week apart, also my sister-in-law is still living with us, it was decided for her to continue living with us allowing her to raise her child and still have her career. My wife is a stay-at-home mother and looks after her nephew and our daughter. Threesomes as still on the menu, as a new mother she wants another child as soon as possible. I'm all in agreement with that and my wife likes the threesome at least as much as I do.