When he gets home, you need to sit down with him and tell him what you found, and ask him what he’s doing. So for now, take a breath. While this is obviously upsetting you, you have to reserve judgment until you hear his explanation from him yourself. I know how tough this is, but there’s no other good way. I know that this is going to be excruciatingly difficult to wait for his return to talk to him about this, but you’re going to have better communication face to face, and this is important.
If you do decide to discuss this with someone — just pick one person. This is not something you want to spread or seek support for from lots of people, until you’ve heard an explanation from your fiance.
It would be helpful to know if he’d been married to his son’s mother, or if he’d had a long term committed relationship with her, why it ended and if any concern about his orientation was a part of that relationship ending. In other words, if this is a secret lifestyle, how long has it been going on?
If your fiance admits that this is a chronic, long term lifestyle that he’s kept secret from you, then I don’t think you’re going to be able to have a monogamous relationship with him. He’s not satisfied with women, he wants men, too. You will never be enough for him. 🙁 This won’t bode well for a stable family.
So, until you talk to him, keep yourself steady and busy. Focus on your pregnancy, and yourself. Don’t sit home alone. Go out and walk in the park, shop, cook, go to the movies, and keep busy.
When he gets home, you’ll be able to get some answers. But this won’t work if he is gay, bi, or something else, and needs to have sexual encounters with people other than yourself, so you need to hear [i]from him[/i] what’s going on.
Hang in there.
Let me know how things go. And good luck!