Stay Calm

If your ex tries to get you upset or angry, stay calm. Don't respond to his\her anger or engage in a confrontation she\he is trying to get you involved in. Be sincere and calm in your response. As the old saying goes, “kill them with kindness” (not literally of course!) Deal with the situation the same as you would with a hostile customer at work. Don't take it personally even though it is directed at you personally. Tell them you are sorry they feel that way but the situation is out of your control, the situation can't be undone, you are not able to discuss the issue with them, or whatever the rationale is.