Ah op I'm so sorry, this is heartbreaking.
I think if I were in your shoes the damage would be already done in that:
- he seriously thinks this behaviour is OK and he's actually happy to potentially miss the birth of his child
- the fact he's prepared to leave you in quite an underhand way when you're the most vulnerable and dependent on him that you'll ever be
- that he's been manipulative and childish in his response to you challenging this instead of acting his age and stepping up as a husband and father to be
- the fact you'll always know he was prepared to do this and that you now know that you and your child are not a priority for him and that's a shadow over your relationship now.
I actually think I'd be raising this at your next appointment so the midwife or consultant can really bring this home to him.
I can understand him being gutted to miss out, and I can understand that for men sometimes it doesn't fully sink in that a baby is coming until it arrives because they don't have the same physical symptoms of pregnancy we go through - but he should be buzzing to become a dad, he should have been the one to say no way lads and be strong in his role as a man and a husband and a father without you having to chase this. It's also the fact that babies are expensive, you'll be on a reduced income and he's spending money on a lads holiday when most men would be saving.
He's really let you and himself down here, and he's shown you that he thinks he can bully you or sneak around you to get what he wants (at your expense and leaving you vulnerable) instead of working with you as a team.
Having a new baby is hard even on really solid couples- lack of sleep, lack of intimacy, lack of time together, lack of fun or variety in life, increase in responsibility all can grind people down and build resentment in a couple so this is something he needs to be prepared for and ready for or he's not going to be the best dad he can be.
If he's quietly freaking out then he needs to talk to you, or someone he trusts, he doesn't stealth book a lads holiday for the time when you could be in labour.
Personally op, I'd be listening very carefully to his behaviour and what he's shown you as opposed to his words and I'd be making sure you have a separate bank account with money you can leave with if you need to.
My ex started an affair the week I gave birth - never would have expected it of him and I was really glad I had money for myself to leave with ds and I never ever looked back. Utterly devastated at the time but it's doable and if you need to do it you will be just fine.
You want this man, you do not need him and he needs to act accordingly because being in a marriage with someone who loves you is a privilege for both people.