Go ahead, though, and think about what you might need IF ex doesn't change his mind again (which he could) and IF the baby isn't his (or if you decide it's not a dealbreaker if it is).....what would YOU need from him before you would feel comfortable and safe with him?
I'm thinking something like he goes to individual counseling for a year, maybe after 3-6 mos of demonstrated good behavior you consider dating him, he doesn't move back into the house until you're SURE, he doesn't hint to the kids about his desire to reconcile (thus making you the bad guy if you decide you just can't trust him again) etc.
It SOUNDS like he might be heading to the right place for a reconciliation, BUT he could just be temporarily fighting with HWW and headed towards making up with her, or he could want to come home to you but not be willing to do the same kind of hard work and personal growth that you've gone through in the last year. Let him prove his sincerity by doing the work.
