Questions: Break Up & Divorce

I don't know if my boyfriend might be right now or not, but I want to be there for him if he does, as he's coming out of it.

Some signs:

1. He's been criticizing me lately for very small things, even the most harmless of comments.

2. We haven't been making love as much lately, even though I've been flirting with him and trying to turn him on.

3. When he comes over, he stays an hour tops, and he usually comes over to get money, pet the cats, and that's it.

4. He's been spending a lot of time doing things with this one roommate of his, and other times he gets short-tempered when I ask him what he's up to or what he did today. And he won't always tell me where he is when I say "where you at?" (I ask him casually; I intentionally don't interrogate him).

5. He's bought new clothes, gotten his hair cut, become more interested in cologne ...but he's rarely around. I'd like to think he's doing it for himself, but I wonder sometimes if he's trying to impress someone else.

6. A couple weeks ago, he randomly tried a really risque new sex position with me. He's never done that before. And a few months ago, he started carrying a condom around in his wallet. He's never done that before either. And I was already 4 months pregnant with our son (planned; he actually told me months before I conceived that he wanted to have a child with me; I happily agreed).

These are just my worries. I've been trying to remind myself that it's equally possible that he's stressed out, and that he probably ISN'T cheating on me. Fatherhood's a big responsibility, and he's planning on moving in soon (he also wants us to get married). I've told him that I respect his space, his independence, and I encourage him to hang out with his friends, especially when he makes noises that he's busy or wants his space - I tell him there's no pressure between us.

Sometimes I feel like these thoughts come into my head and they're hard to get out. He's cheated on past girlfriends. But he told me he will never cheat on me.

I'm trying to remind myself that he is not. But to put my crazy thoughts to rest, I'm accepting that if in the worst case scenario he IS cheating, then...

How can I be supportive of him? If he's cheating, then I want to be understanding of where he's coming from. I don't just want to be angry or self-righteous. Maybe he's really stressed. What can I do to coax him to share what he's going through? What can I say? Do guys want to be given space once they cheat, to figure out what they're feeling? Does it do them any good to be asked if they're in love with the other woman? How do you have a conversation with someone once they've confessed to you? What are the best things you can say? I want to be ready in case that ever happens.

Men who have cheated ...what would have been your best-case scenario once you were found out or once you told?What would have been the best conversation you could have had with your S.O.?

I appreciate your advice.