Op, I've changed my initial vote from YABU, to YANBU after seeing your first update, and now it's a hell yeah, YADNBU after your further updates.
I'm not going to pile on to your not so "D"P, as pp have already done that for me. Sorry, cannae help masel - he's being an arse about the whole thing! He can go swanning off, but you cant, (you don't even get a break whilst he is there) and the wee one's too young to fly - what utter shite! He won't help at night, cos he's working? Well he made the baby with you, so he takes his 1/2 fair share of the good and bad bits. Don't even get me started on the assumption that of course you wouldn't even consider going to your friend's 40th b'day. You can and should go & he needs to deal with caring for HIS baby when you are away.
@AmIThough: Go home when he's at the wedding and go for your friends 40th!
This up arrow thingy, was going to be my short and sweet post, however ….
He sounds quite a cleverly controlling person, it all appears so, so very reasonable when he says things like of course you're not going to x, or she won't/can't manage that, so on and so forth, because he will always couch the comments to himself, you, and more worryingly/importantly to others, that he only says/thinks/does these things/speaks/decides for you FOR YOUR OWN GOOD. She's so tired after having the baby, im a bit worried for her health …. she needs a rest so gallivanting about isn't such a good idea for her now, so we're staying at home to chill etc.
I think he's using reverse psychology on you as a way to subtly control you, all whilst appearing as the perfect gent/partner/all round good guy, which will make you agree more easily to things & not even realise he is controlling you by stealth. It's only later when you think, I actually wanted to go on that night out/have xyz to eat from the takeaway/watch that programme/veg out this day/visit family & friends on my own those few times. So when you do say later, well no I'd actually quite like to go, or I am going, he can say things like you're being unreasonable, it's too short notice, you're so flaky chopping and changing your mind about things, moving the goalposts or my favourite BUT WE AGREED, to the thing/outcome HE decided, so then he can throw a strop, and you're left never knowing if you're coming or going, and permanently walking on eggshells and not sure why, cos I mean, he's such a good guy isn't he???
So, there I've managed to massively self project (sorry not sorry), but maybe I am completely wrong, and you aren't in danger over the coming years in this relationship of losing yourself, your wants, your needs & your voice, and he will be absolutely fine with you saying, Wee one's passport is ordered, flying home on these dates with them, and flight's booked for pal's 40th, smile sweetly and pass wee one over as oops, think they've filled their nappy with a bit of a wet one and it's your turn. (I hope I'm wrong.)