Whatever you decide to do over the weekend, I know you will handle it with grace and dignity. You've got this! You are stronger than you think.
I do understand how his being nice grates on your nerves and patience. I use to think that my xh being nice was his way of getting me to open up about what I am doing and w/whom. I also think that deep down, they think that if they are nice to us, we'll continue to do things for them. Keep in mind, being friends w/a MLCer is a whole different type of friendship. True friends don't treat their friends the way that the MLC friendship is carried out. Their empathy chips are broken and they don't realize how we actually feel about what they've done.
I am sorry that your daughter's father didn't share the news of being remarried w/his daughter, but I do hope that they can mend the fences and stay in contact w/each other.
Coly, you are a beautiful person who is kind, compassionate and caring. Please do not allow your h to create doubt in your mind whereby you second guess yourself. He's a broken man and you didn't break him.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.