People who stay in unhappy marriages for the sake of their children are making a huge mistake. Unless divorce would put the children in harm's way (abusive parent, extreme poverty, etc.) it is best to part ways, and here's why:
1. You are modeling what marriage is. Your kids will learn that being married means being unhappy and not loving your spouse. In the future, they may opt not to get married at all or subconsciously attract a mate that will be oppositional just to replicate what they were raised to think marriage is.
2. The daily misery creates a toxic home atmosphere. Nothing needs to be said for the kids to pick up on the tension and distance. Especially when the parents "hate" each other. It's one thing to get along with respect for each other, but to hate each other? That is something you can't hide.
3. The parent-child relationship will be negatively affected because even though you may "hate" the other parent, that person is someone whom your child loves.
4. You may think you're doing this for the kids, but ask any adult kid if they would be glad their parents stayed together for their sake and the answer is a resounding NO. They report that they would feel guilty for being the cause of forcing their parents to stay together and forego their own happiness.
5. Adult kids also report that they would feel betrayed and cheated because of the false front put on by their parents. They would hate to learn that all those years together were a fraud.
Ask yourself why you're staying for the kids? Are they really better off in a home environment where their parents are unhappy? Because to them, all the other reasons to stay together don't matter if their parents are unhappy. With that said, married couples with children really need to get their act together because they're showing their children that you can stop loving someone just because they fail to meet your expectations. That you can just cut off someone you once loved. And that scares the heck out of children. Does your love for them also have strings?