You've got an ex who is still part of your life. How do you explain this to your new man?
These come in two flavors, ex-spouse who is now a close friend and ex-spouse that you share parenting duties with.
How do you explain an ex that you are still great friends with outside of any parenting role? You pretty much can’t. It will constantly be a pebble in his shoe. It doesn’t matter if your ex is remarried or both of you swear that the relationship is long over. You have to ask yourself, “what role is that ex playing in your life that you can’t get from someone else, and does it leave room for your new man to take that role?”.
For shared parenting duties the explanation should be easy as long as you limit your joint activities to purely parental and begin to systematically increase exposure of your new man to your kids.