I'm another person whose parents didn't split and in many ways i wish they had. They were happy, then she got ill. She was mean after she became ill. Twisted and manipulative. It probably wasn't her fault, it probably was a result of oxygen deprivation during heart attacks and her stroke or changes from the chemotherapy and radiotherapy (she had 2 unrelated terminal illnesses). It was a really hard thing for her to go through for sure, she took it all out on my dad. She would turn him inside out with her destructive observations. He was on anti-D's and in therapy for 11 years to keep sane while staying married to her. He once went to stay with his mum for 6 weeks as his dad had been put into residential nursing care and she needed support for the transition to living alone, she told him not to come back then phoned all her kids and said he'd left her. I cried wholeheartedly about it then felt quite optimistic. I called him at gran's and he was shocked to learn he'd left her! She twisted so many things - she bitched about him so often to me i once said "if it's so bad then stop complaining and leave him" and she later told him "your own CHILD thinks i should leave you!". It really hurt and damaged him, but i guess i found his loyalty and kindness inspiring too. He never left her, in the end she died, and he stayed up with her in the Hospice that night, holding her hand and lifting her back into bed when she screamed for her mama and fell out of it. It has left him incredibly damaged. I'm glad she had his love right to the end, but i wish it hadn't cost him so much. She died nearly 6 years ago and he has told me he's too scared to ever get into another relationship in case it happens again (the illness, personality changes and death) or in case it happens to HIM and he puts someone else through it. It kills me that this sweet, loyal, loving, amazing man is alone because of the damage not leaving did to him. My mother had been divorced once before. She stayed for 15 years with a man who beat her in front of her eldest 4 kids and finally walked out when he threw her down stairs and her eldest son saw it and didn't react at all. She was horrified to think she had allowed them to be witness to it and become so numb to it.
So my parents stayed together. I split from XP though, when DD was 8 weeks old. She was not a planned baby, she was a cheeky wee surprise. We would have split whether she came along or not and neither of us regret her or the split. But then, we are friends. We fought a lot and couldn't make it work (we tried, but things he couldn't relinquish, like drug use, were not things i could compromise on when we had a baby in the house). Now we are good friends. DD does go back and forth, but it is very worked out, very stable, but flexible to her needs. She doesn't get 2 parties - we have parties together, ditto Christmas (he comes to us in the morning, then we drop him at his folks when we go to MIL and FIL for lunch), we talk daily, we eat together at least once a week, i frequently cook for him (sent him home with soup tonight for example). I don't know what impact it will have on DD. How can i? But there's not a lot i can do about it. It might make me unbearably selfish or a terrible parent or both, but my long-term unhappiness is not a trade i'm willing to make for my kids stability, and i don't believe it would be a worthwhile one if it was. Children learn what they live. I was never going to raise my DD to think love is indifference. To believe control is a major component of a "good" relationship. To think sacrifice of everything, even one's happiness, is a necessary expectation of a partner so THEY can be happy. To think compromise is a one-way thing women do to make men happy. We are great friends, XP and i, but we were NOT a healthy couple.
I'm not too sure on the "morality" of leaving/staying. I was not and am not married. I don't believe in a God. I didn't promise anyone anything. I believe as a parent i am charged with providing a stable, loving environment for my child and as far as i am concerned i am doing that, it's not a "make-do" situation, i am in another relationship but i was dating this man, who i had known for 5 years before we began dating, for over a year before i let him and DD spend any time together. I was extremely careful. I make my choices carefully, i listen to my child, i make changes wherever i see they are needful and i am always open to revisiting things as times change. Decisions are made with the 3 parents and the kid all having a voice (DD2 will have a voice when she can talk too!). Overall i like how we all get along. That it doesn't fit the mould of a different person or society with a different moral code is...irrelevant. I can't answer for the studies. I am not a demographic. I am a person, doing my best with the cards i got dealt. I'm really proud of myself, of my XP and DH and especially of my little girl.
OP unhappiness is not a habit you want to teach your kids? Is it? :hug