Keeping it in the Family

I married at 22, started living with my in-laws. My wife (20) quickly got pregnant, so her mother (46), a widow, started sleeping with us. Just after the birth of our daughter, my wife's sister (24) joined us in bed, and she also got pregnant. Now eight years later, I have a daughter and son with my wife, and a son with her sister, who is pregnant again, and we are happy with our family arrangement.