Personal advice

You've just gone through an enormous physical, mental, and emotional change to give him a child, expecting you to be ready for sex just two months afterwards is insane. If he respected you at all, he wouldn't have done it, and who knows if he would've even told you if you didn't find out. I couldn't have sex for a year for medical reasons, and in that time my husband never did anything of the sort. Personally, I would have no interest in being with someone with so little self control or accountability.

Without him acknowledging what he did is wrong and showing remorse, without excuses, I don’t think you can move past it.

You shouldn’t have to feel pressured to do something sexual with him in fear that he will look elsewhere. It means he’s not present with you in what you’re going through and not being a good partner. I’d find it even harder to want to be sexual with someone who is not with me through that, let alone when he’s looking elsewhere.