If you want to raise calm, well-adjusted children, this is perhaps one of the biggest keys. The providing of a common front limits the ability of your children to play you off one another. Understanding what your spouse is going to do and supporting them is a key to providing structure and normalcy. There are three ways this works out. 1. One of the parents is dominant, and operates as a benevolent dictator. 2. One parent is dominant in defined areas. 3. You play the “go ask your mother”/ “go ask your father” game. What you don’t want to do is have one parent dominant, and have the other come in. It’s even worse when one parent is usually dominant, then asks for the help of the other, the other asserts themselves, then the original parent undermines and says the kid can do what it is. At that point the second parent is undercut. It just doesn’t lead to good things. The kids now see a rift that can be exploited, and the second parent is going to question getting involved in the first place. It’s a good way to alienate each other and teach the children that one parent is going to side with them, or start a fight in front of the kids.