Family History of marriage failures

I'm John 37 divorced, I've a sister Jean 34 divorced and it seems to run in the family. Our parents were divorced and grandparents as well, so it should be surprise that our marriages failed also. But ours marriages were a little different to theirs, we hadn't any children from our marriages. Unlike our parents and grandparents, who stayed married for more years than we did and had children. Jean had married Robert and Robert was a woman chaser and they got divorced no children. Robert wasn't all that well off and that Jean looking for a job as she couldn't still work near Robert. Robert was more important to the company than she was. Jean was looking for a place to live and find a new job, I was already divorced. Had my own home and a good career, my divorce was fair and I didn't have any alimony payments as my ex also had a good career. So Jean moved in with me, which was good for me as she done my cooking and laundry while looking for a job. We then had a hurricane come close, but didn't affect us directly. A heap of rain and some flooding in low areas, nothing close to us. I worked from home so not to travel back and forward to work at that time. Being around Jean more often as we were when younger, we started mucking about a bit like we had before. But we were now older and when her top came open I suddenly saw her as a woman and not just my sister. So I kissed her, she was little shocked at first. But she got over it quickly and kissed me back passionately and I responded by getting more passionate. I fucked my sister on the lounge room floor and then took her to my bed. Sex became daily for the next week and of course, just being divorced she wasn't sexually active and hadn't taken any precautions and neither had I. So she got pregnant, which was a shock at first. But after thinking thru, we decided to see if us being siblings affected the child. It didn't and Jean wanted to have the child and I said I would support her in every way. Our son Jason was born healthy and we had continued fucked before and after his birth. Jean changed her surname back to her maiden name and so it appears on the birth certificate like she is my wife. Jean has been a great mother Jason and has again tested positive to being pregnant, again we will await test results before deciding what to do.