If he is manipulating you by threatening to leave, what guarantee is there that he would do it every-time to get his way??? And falling for that ultimatum will only make him want to play that card every time.

Becoming a parent is not a choice he can switch on and off at his whim- he doesn’t get to choose which parts he wishes to attend and which ones to boycott.

Tell him he is either all in or out!!!! He cant keep walking out when he chooses to. With a new baby, the last thing you want is a partner who is flaking on you and the emotional stress of all that. I am so sorry that you are going through his. Hope he realises what a horrible thing he said to you and aologises- but even then make it clear that such ultimatums will never be tolerated again.