Traveler provided some excellent advice, I would hold off on having that convo until much later in the game when it's evident your H is able and willing to make an effort to repair the relationship.
Anything convo related to logistics, children, finances etc is fine. But I strongly suggest you do not initiate any kind of relationship convo/obligations at this point.
I always liked the squirrel analogy in this board. If you want to have a squirrel eat out of your hand (ie attract H back), you allow it the freedom to come and go without spooking it. If the squirrel finally gets enough courage to eat out of your hand and you go to pet it (ie have a relationship convo), it will quickly bolt back up the tree and you will have to earn it's trust all over again. Let your H come back to you without spooking him.
You will absolutely know when he is ready to have a relationship convo because he will actually bring it up.
