Spockette picked up on his behavior seeming to be aggressive. I think she is on to something.

It seems to me that your H is not, in reality, interested in any of those other women.

He is, however, very keen on getting a rise from you.

In essence, he has found a button in you and keeps pressing on this button because he enjoys hurting you. And that he likes a LOT.

Ideally, once you have determined that he positively enjoys hurting you, you should leave him for your own good, and find a more peaceful man.

However, to the extent that you might want to explore and exhaust your options, I would recommend attacking this issue in a rather paradoxical fashion.

Tell him that you do not care. Stop violating the terms of service of Facebook by hacking his account. Stop that (you will respect yourself more anyway if you stop violating the terms of service of Facebook). Tell him that he can contact whomever he wants and like whatever pictures he wants to like that are not yours.

See what happens. Once you remove the forbidden fruit element, he might lose interest. Also, once you stop being as vulnerable as you currently are, he won't be able to press those hurting buttons. One cannot press buttons that you do not have, and you have some control over what buttons you do have - exercise this control.

Do that for two months. In the meantime, observe his interactions with the baby. If you see some promising signs - say, he starts changing diapers and start smiling to the baby - then continue on. If he remains unresponsive to the baby, then leave him for your sake and your son's sake.

If you do decide to leave him, be happy that it is happening so soon. Would have been worse to waste more years on this guy.