I agree with Lotus, its important for LBS's to make themselves the better alternative... the by-product of that is that very often we become not only a better alternative, but a better person in the process.
When you get there the goal is Zero pressure. No I love yous, no holding hands, be careful with making love, you need to make him miss being your H, if you prepare dinner, dont serve him. If you are taking the kiddos to do something fun, make sure that you mention it in front of him, but dont directly invite him.
No matter what happens undefeated, if he says that he wants to try again... Dont rush in. Be extremely cautious! Im not saying that he will try to fool you or whatever, but its really easy to rush into these things and make mistakes that sabotage all of your hardwork.
You need to set boundaries, "I will not share you with another woman". And you need to learn to validate what hes going to say. If hes venting about things that you "never" do, or "always" do, just validate, you dont have to agree(mostly because hes probably not going to be right!), but you do need to show him that you respect his feelings. Just say, "I understand how you could feel that way" If he says this will never work, or theres too much wrong to fix, you say "Im sorry that you feel that way."
Dont engage him in arguements, this is a big one! If things get heated, leave the conversation, leave the room, leave the building, just get away from it, arguements are emotionally charged, and we dont make good choices, or logical points when we lose control and get emotional!
Most of all, I know that your fam doesnt know whats going on here, so reach out and use your support group, be it us, or old friends, whoever it is, make sure that you dont try to take it all on yourself. You will turn into a basket case!
I think that your going to be fine my lady. No matter what happens.
I guess I gave the wrong finger to the wrong man...