Well here's the thing;
A man needs to know that he is everything to his wife. He needs to know that she thinks he is the bomb, the STUD, the fixer of everything broke, the king of the cabin, a man needs this. It is all in how you manifest the love. If a woman loves her man she is going to learn how to show it to him in the way that he can receive it. Then he will have a deeper love and compassion for her love and commitment to her children.
Men may come and go, but your children are your children forever. But to all live in harmony a man needs to feel like a man. He needs to be respected by the children, biological and step children. The parental unit has to stay united and support each other.
Now if one person is asking the other to sacrifice the children...well that's a very bad situation. Then a parent may need to chose the child over the partner. I've been in that situation and it ended pretty ugly.