Gordie - For yourself this is another betrayal that you will need to deal with. If not OM2 then OMX etc. Your STBX shows poor judgement in pushing another man into their lives even before your chair is cold. But - well - that is what it is.
I wrote before about mind-shifts where your STBX is no longer "your" wife/ex-wife but where she is the "mother of your children". Somehow you need to find a way to distance yourself from this guy as well.
It sounds like he will have contact with your kids sooner rather than later and that it's not being done in a thoughtful way. No matter whether he tries to be a "Disney Dad" or is a guy who will ignore them, stories will get back to you. I haven't had to face this myself but I've read lots of places where it happens. I recall some old threads by CT1118 where he worked on dealing with this with his young son. It's tough.
Hopefully some of the others who are dealing with co-parenting will chime in. There are a fair number here.
I've said it before and I'll say it again. This is the toughest thing that you will ever have to do. It takes a very brave and very strong man to take what you have taken with the grace and courage you have shown.
On BD H52, W50 T27, M26 S21, D23 BD-9-Mar-16 D-15-Jan-18 Final-19-Apr-18 I am a storyteller. The story may do you no good. But a story is never for the listener. It is always for the one who tells