Your co-parent might be a little arrogant at times, but is he a narcissist? A narcissist is someone who draws "Erotic gratification from admiration of his or her own physical or mental attributes," according to according to Dictionary.com. In other words, he can't get over himself! And he knows exactly which buttons to push and exactly what to say in order to drive you nuts. And as if that weren't enough, his abuse can damage your children's emotional development. While it will be nearly impossible to separate yourself from him completely, because you have children together, take heart. You can take some steps to make the best out of a bad situation and avoid strangling him.
Don't argue with him. This might be a hard step to follow, but remember: You can't make narcissists see that they're wrong, and trying to win an argument with them is pointless. Restrain your competitive side and focus on what is best for the children. Keep your communication with him as brief and businesslike as possible.
Don't try to change him. The treatment of a man's narcissistic personality disorder -- the technical term for narcissism -- should best be left to mental health professionals, not to his former life partner. Accept that he might never change, and interact with him accordingly.
Set limits. Ensure that you don't allow him to intrude on your life and the lives of your children in ways that are disruptive. If you are in the midst of custody proceedings, get every aspect of his visitation and custody rights in writing. This might seem like a pain at first, but remember that narcissists are masters at lying and spin, and everything that is not in writing could be fair game for him to dispute and argue with you, which can only benefit him.
Don't let yourself be provoked or manipulated. You know he'll do anything and everything to push your buttons, but how you respond to his antics is in your control. Take a breath and count to five before you do -- this will help you think more rationally about the best way to handle the situation.
Seek professional support for you and your children. The narcissist is toxic, and it will help to have a trained professional help you and your little ones recover from his abuse and begin healing.