Statistically speaking it's VERY unlikely their relationship will last (she's probably in post-partum depression). There's absolutely nothing you can tell him to make him realize that. He will have to figure it all out on his own. If you try to talk or convince him of anything he'll only focus on you and anything he can twist as negative about you and him, rather than his own situation. Your best bet is to wish him happiness, and tell him you're glad he found happiness, and then let him go and mull over if he truly is happy, thus giving him the time and space to really focus on whether this really is such a great situation. Unfortunately it will probably take time....
There is no arriving, ever. It is all a continual becoming.
