I have yet to find an end to the stupidity that comes from my XH.
As the years of separation pass, you will come to understand WH's selfish action is not about you or the kids or anything except the nonsense that resides between his ears.
For now, steer clear of any interaction, direct or indirect, involving WH. You deserve the mental break from listening to and deciphering who he is with, what he is doing, etc.
It is not going to be possible to dictate who is present when your WH speaks with your children. One of the hardest things I had to come to terms with was that when my DS is in my XH's care, he will be exposed to whatever/whoever XH deems appropriate (within basic child welfare standards, of course). It is a tough pill to swallow, but, in my case, was better than exposing my son to a daily example of how a marriage should NOT work - cheating daddy, bitter mommy, arguing, crying, etc, etc, etc.
Hang in there - it gets better.