Delighted to read it will be a twat free zone and that you will not be in any way involved with transporting the children.
Start as you mean to go.
Do not entertain it for a minute.
Infact treat any suggestion by him with incredulity....as in, that's got fxxk all to do with you🙄.
I would also instigate all communication regarding the children through email.
Give the boys both phones so they can communicate with you directly when with him.
Tell the boys they need to be packed and ready with everything by the door for when he calls.
Limit interactions with him to the minimum.
Your boys sound great.
Do as @RandomMess suggests and be honest with your son.
He will understand.
Children understand a lot more than we often give them credit for.
You can pick a nice day and designate it as his postponed birthday.
Make his favourite dinner this weekend.
Well done for the email re costs.
He no longer has power over you.
You are nearly free of him.
A great future awaits you.
He's got to go looking for wife number 4!!
Pity the poor idiot that entertains him, god help her whomever she is.