Ex becoming very awkward since the arrival of his new baby with new partner

I don't think he's being unreasonable to point out that you going away will impact on his already very limited time with his son. Why does he only have him once a week? I would offer him another night each week as standard anyway, and see if he jumps at the chance or makes excuses. And offer an extra night the week before you go which would give you some extra time to organise your things. Now he has another child it might just be that he needs to be able to make arrangements that are less flexible. That's not necessarily him being difficult.
My ex was brilliant up until just over a year ago, and we had maintained a mostly good relationship until he moved in with his current girlfriend. Then he stopped prioritising our kids and I completely lost all respect for him. My son now doesn't see him at all, and my dd sees him for 8hrs every Sunday. In all honesty it's not worth fighting him on it.
Your ex's relationship with your son is his responsibility not yours. But you need to make sure it goes both ways while he is still so young. It does sound a bit like he has swapped things around to help you out but you don't want to do anything to give him back the time he loses out on while you are away. Offer him more access rather than less and his response will show you if he genuinely wants the time with his son or is just being difficult. And put a time limit on the letter, if he doesn't send it to you by then as a pp said approach a solicitor. But if your son has the same name as you I doubt you would be questioned.

Tell him that you will make an application to court for permission to take your child on holiday unless he gives you the letter. The court will no doubt approve your request - you are a safe parent who is planning to return to the country, and it is important for your child to develop good relationships with extended family members. Don't cancel the holiday.

Btw I wouldn't take it for granted that he is happy. He is at the stage now with his new family that he was at with your family when he left. I imagine it irks him to see you are happy, meeting someone new and planning exciting holidays, while he is stuck at home

When my son’s dad had a baby the same thing happened- he went from seeing him 1-2 times a week to every other week. But at least he can say he still sees him
blows hot and cold in conversations depending on whether he and the “mrs” have had an argument.

tell him that NZ is non negotiable and he can have extra time before and after

I agree with pp one more email/conversation stating the plans and asking for the letter. Simply add that this is to see you sons uncle and a family holiday

then go the formal route

don’t bother wasting your time trying to reason with him or pointing out he only has his son once a week he is being unreasonable. I wouldn’t try to work out why he is being the way he is as you will never truly know. Deal with the situation not try to work out what is going on it’s wasted energy

Always give baby your surname
Tell him he can have your son for the 2 weeks and you go to NZ. Because you know he will say no, or the new women will

I thought this too.

Guilt can come across in really weird, angry behaviour sometimes.

Does your ex never plan on taking his eldest son on holiday then?

A letter of authority needs to be formalised. You’ll have to do this every time you go, which usually means solicitor fees. Honestly, I’d just go straight to the court and bypass his dickish control.

Whatever happens get a CAO in place, then you can take you DC without permission for up to 4 weeks.

I'd also get contact arrangements formally agreed, EOW or whatever.

I read your OP and my first thought was that he feels like an arsehole for leaving you when your baby was 2 months old, like this one currently is, but can’t cope with the guilt so he’s taking it out on you. Add to that, you’re moving on with your life: holding down a job successfully, dating again, planning a holiday with your family and it’s a further reminder of his failure as father and partner. So he doubles down and keeps on behaving like a cunt.

Agree with others about the CAO. It’s a shame these things are needed but it’s better for everyone especially the children involved to avoid messy battles over care etc.

I think fixed contact is not unreasonable..though I'd be asking him to do more than one night! As to the holiday the easiest thing definitely is to say well either DS gets on the plane or you have him for two weeks. Choose. I know it's not what you want and he almost certainly won't call your bluff but if he does, you get a much needed break, DS gets to know his half sibling and your ex might actually start to get a clue about what an actual parent looks like.

I would suggest one final conversation with him just before you go down the formal route so that he understands that this can work both ways - I.e so far you have both been co_parenting practically and flexibly for the sake of your son but if he wants to formalise it, it’s going to remove that flexibility on both sides. On the holiday front, I would highlight that two week holidays are perfectly normal and reasonable and it’s not realistic or fair on your son for him to never go abroad on holiday due to his parents personal circumstances. It would also mean ex cant take him away in future as it works both ways. The other thing to highlight is that once children get to school age, they get invited to birthday parties/sleepovers etc which again requires parents to be flexible on arranged days for the sake of their child not missing out on normal social activities. Good luck!

I think making it clear that if he torpedoes your holiday you will be dropping DS off at his house might focus his mind.

Let him know that - as DS won’t be able to go on the holiday - you’re happy for him to stay with his dad the full 2 weeks whilst you’re away! Tongue in cheek - but I don’t think that’s entered Ex’s head. Yes, you need to pursue a more formal agreement to prevent ongoing issues

It would be nice to think that he'd seen the error of his ways, but people often don't change, so I'm going to offer an alternative view. Clearly for your ex, when the going gets tough, the tough hide under the table (can't remember exactly where that's from but it fits the bill here). And the lustre is probably wearing off his "shiny" new baby, just like it did with his first DC, and he's beginning to feel trapped again. Who knows, he may be gearing up for another walkout?

And then he looks at you and your child is easier and older, you're past the most stressful stage and you seem to have your life together again (no thanks to him). This may be unsettling for him, given he may be feeling "trapped" in the hell of small baby land again, so he's trying to make things difficult for you.

Personally I'd apply for the order so you're not at his mercy.

Hmm yes. He’s a dick. I’d text him I’ve noticed you’ve decided not to be flexible anymore with my shifts etc. I understand you didn’t have to, but it was very helpful as a single mum who needs my job. I am going to apply for a child arrangement order to get legal permission for my nz trip, I assume you’ll get some notification.

maybe now he has another one he realises only assholes walk out on their partner when they have a two month old, and his channeling all his guilt into being angry at you. Maybe you should add to your message ‘say hi to <new gf> for me and remind her that when <baby> was this old you walked out on us and left me to it with our 2 month old. That was a really shit time. Please stop being so shit. I’ll be taking our baby that I brought up pretty much on my own to nz to meet my family, you should concentrate on not walking out on baby 2 too instead of continuing to be a dick to me.

ok you shouldn’t write that but wow it would be hard to resist.

He'll be regretting the new woman... they always do. They realise the grass isn't greener and wish they had stayed. They are then jealous when you move on. The new woman/step mother then picks up on it and becomes insecure, often taking it out on the stepchild. I've seen it so many times.

As an pp said, get a CAO. It will give you back control.

... seems really angry that i want to take DS to NZ, saying that itll tske time away from him having DS...

He has his child overnight (not even 24 hours) ONCE a week; that's less than 15% of the childcare. I'd want to know what's stopping him from doing his fair half EVERY week before I worry that he'll miss two weeks.

Probably any of those things but also he might be a bit put out that you get to do the dream holiday without him.

I think you need some boundaries and clear expectations going forward. It might not be as flexible but you'll know where you stand.

I wouldn't rely on him to change the day around your schedule- that's a favour and it gives him the power to withhold it.

Just set a day and stick to it.

It's completely reasonable to take your DC to see family in NZ and it's in your child's best interest to be included in extended family plans like this. That's what a lawyer/court is likely to say. NZ isn't a country where you could legally abscond with the child.

I'd pay the money for a formal contact agreement that you both sign. He'd be advised that he's unreasonable to withhold permission for NZ and you're likely to win if going to court is required.

Ok well bearing in mind he does now know and is being a dick, the obvious solution is to say he’ll have to have his son for those two weeks you’re away OP. I bet he’ll change his tune at light speed 🤣

@MoonCircles I think it's fine if dad's OK with it or doesn't know, but if they do and are not happy, they can cause you big problems. My solicitor said they can put a block on your child's passport, alert border patrol, and even fly you home early. Granted this all seems extreme but it would dampen any holiday excitement!

I have travelled all over the world as a single parent with two DC, and never once been asked for any kind of letter of permission from their fathers. They do both have my surname though, although one is double barreled with her dad’s. So maybe that makes a difference. But honestly it’s not something I’ve ever given a second’s thought to before travelling.

If you hadn't told him about the holiday I'd say go, but now you have he could make it difficult for you. It's child abduction which is ridiculous, but sadly true.

I've just been through court to go on holiday and honestly I'd avoid it if you can, it's a can of worms I'd rather not have opened.

My ex did exactly the same, saw me with a bloke (not even a boyfriend, a good friend) and started being awful. The holiday refusal came shortly after.

I suspect it's a territorial issue about another man taking their place in their child's life. Neither of them seemingly wanted that place when they had it but I guess that's mens logic for you!