Dawn hits the nail on the head.

Over at The StepfamilyLife, Dawn, articulates (so well) what happens to the child when their other parent is being dissed.

When you speak poorly about your child’s other parent, you are hurting that child’s self-worth. How can a child look in the mirror and see a reflection of both his parents inter-mingled - and hear someone saying bad things - and not have a poor self-image or feel conflicted?

She writes straight to the point about how the kids literally feel the way their parents are treated. It reflects back to them, and that is how they see themselves. This is the very basis upon which they define their personal character. And this is a character above all that we must nurture.