my opinion is to show parenthood as a joy and don't expect anything from him. You're probably already doing this.You could try to liven things up, but that would really not help with your detachment. I say do whatever you can to detach and then focus on bub!
I agree with Gatsby...
Basically, just be yourself, be genuinely happy and the glow will exhude from you and if nothing else you will feel better about yourself... (hopefully H will notice and taste the sweetness).
I wish you continued stregnth... i would imagine its hard to see him go, and make such a move. But put yourself first! Take care of yourself. Do things out of the goodness of your heart, no spite work, and if you have something to say before he goes, just tell him.
Sorry, dont know if my opinion makes sense...
I really want to say, Club him upside the head and drag him into your home and never let him go...