There are four ways to foster a healthy, cordial relationship to your mates former wife or husband:
1. BE CIVIL -if you think that you're about to say a negative one,find a way to re frame it.
2.BE CLEAR -say what you mean,but say it carefully by starting your sentences with "I"instead of "you" and avoid absolute statements such as "you never"
3.BE COOPERATIVE- don't you know that children are involved,so its imperative that you find ways to work together regarding schedules and family plans
4.BE CALM - never raise your voice.regardless of what he /she says resist responding with something you'll later regret.