Planned a long response to you whilst eating my breakfast and then thought I'm just going to write what I'd say to you if you were here in this kitchen.
Team FS is broken. You have expected because he's a good Dad, he will still be part of the team. He has expected that he can live a separate life and still be part of the team. That's cake eating.
Now, it should be possible. There are people all over who manage to maintain a healthy team ethos even when separated. The fact that he isn't, gives testament to his character at the moment. FS and the girls can be in the team and I'll dip in and out when I want.
You may have to accept that is the way it's going to be. Yes, it's disrespectful to you, but in his eyes this isn't about you, it's all about what he wants. Perhaps you have thought that the girls gave you the opportunity to stay connected to him? Perhaps he doesn't see it that way. There's no you and him, just him and the girls? When he wants.
Perhaps you need to drop all expectations of him. He's coming up short.
I get the distancing / openness dynamic, but it is leaving you vulnerable to his selfishness.
Perhaps just carry on in a friendly but detached way but drop the expectation that he is going to be an all in team player.
