I agree with Calibri -- step 1 is to speak with a lawyer. You don't have to pick someone to represent you this week, but you do need to get some advice. You will almost certainly be able to find a few family law attorneys who will give you a free consultation. Try to get 2 or 3 opinions before you talk to H. Remember that nothing is certain in the law, but if 2 or 3 lawyers give you the same advice, you can probably rely on it. It helps if they are very local and know the family court judges well.
Step 2 is to examine how you feel. I know you're reeling from the Facebook discovery, but are you 100% sure you are done? If so, then it doesn't matter what H says or does during the meeting; your mind is made up. That's easy (or at least, easier). But if you're not 100% sure, then I think you have to decide what your boundaries will be during the conversation with H. That's much harder, I think.
The cynic in me thinks that he must know you've discovered his second Facebook profile; the timing is just too coincidental. But if we ignore that for a moment, he is asking to talk, which is a 180 for him, right? I'm not saying you have to be open to him or anything he has to say, but I don't think you'd be a fool to listen to him, either.
