What's a reasonable reaction to your ex-wife keeping information about your child from you.

Okay so let me unpack this. This is related to my previous post about a dad who finds out his co-worker is his daughter. I'm thinking of adding the twist his ex-wife knew about her and didn't tell him.

Background. M47 is a coach from the US and works in the UK. He finds out co-worker F30 is his kid from a high school romance. He returns to the US and F30 goes with him to help him move and then she's going home to her boyfriend M38. They stay with his ex-wife F46 and his son M8. The ex-wife is insanely guilty over the fact when his daughter was about 14, her birth mother attempted to tell him about his daughter. The ex-wife actively shut it down and didn't say anything for years.

This is a pretty big betrayal. I have F30 find out when the ex-wife is drunk and wakes her up to confess. The daughter goes feral and slaps the woman. Her father steps in and carries her out of the house to prevent an assault but honestly, I don't where to go from here.

Currently I have father and daughter literally sitting in a McDonalds parking lot. Not sure where to go. What do you even do with that information? What's a reasonable place to take this?