Part of my and my stbx wife's problem is that her father did not protect her from the new stepmom. Stepmom wanted dad all to herself and let it be known. This lead my wife to withdraw and she survived the life. She learned to keep her feelings to herself. Combine that with me who never had boundries growing up. I stepped all over her and she held it in until she could not any longer.
My point is that the kids need to be loved by both parents and any new folks. If you can't love a child you really need to look at who you are, is this the person you want to be? Do you want to be with someone who can't love your children? The children are hurting enough... grow up. I expect my stbx and I will have others in our lives, at least mine better at least respect my kids. I have no use for a woman who's mean to any kid... I don't care now hot she may be.
If you want to stop the cycle of divorce in your family you need to pay attention to the kids and educate they to your mistakes. I will have no secrets with my kids. I want them to marry once and for life.