To think DH is insane to suggest this

I’d be happy for him to pop round there with your DD - maybe do presents and family breakfast with DD in morning then he pops round from 10-1 or something while you get yourself sorted for the day? Then he’s back for your family coming over for dinner etc and you’ve got whole day/night with your DD?

Why can't you alternate as I suggested, OP?

I'm sorry OP, I haven't read the thread, just your original post, but I think it's absolutely ridiculous that your partner's ex thinks childcare arrangements for Christmas would change just because she's single now. Also that your partner is just going along with this, is nuts. If I had a really good relationship with her, I would invite her to call in on Christmas day, but it doesn't sound like that's the case. Does your P always allow her to just make decisions?

I think you need to approach this strategically and think about how whatever happens this year is going to have a ripple effect down the line.
He's still got care and compassion for his ex, which yes is grating as he's putting her first. He also needs to get his head around how he's made you feel irrelevant and second fiddle.
I do wonder if she's told him that she will stop him from seeing his boys completely if he doesn't let her have them all day.
Whatever, you need to decide if this is a deal breaker for you. If this is really how he sees you, are you willing to put up with always being second best and second thought? I could understand if it was the kids coming first, that's the only time I think it's acceptable to have your partner not your first priority. Only here it seems that he's dividing his children into different priorities too, and his wee un is lower in the pecking order. Essentially, first family comes first scenario.
If it were me, I'd hold my nose and ask her round for Christmas lunch, no matter how much it stung to see my supposedly DP playing happy families with her.
I'd also be having a big think about whether I wanted to be in a relationship with someone who didn't make any effort to understand my feelings over this.

There's a very simple solution!!!

What - see her siblings?

I think him taking DC to see them for a few hours is a pretty good idea tbh. Xmas day can be pretty long, your child will probably be up early and presents will be done by 8am, dinner at 4ish. I think him taking them to see older siblings early afternoon would be good, they will be excited to show their siblings a few of their presents and you can get organised for dinner. Ideal really.

Yeah and a lot also wouldn't, especially with such a big age gap between the siblings.

Lets also not forget that this isn't nana and grandads house or a close family members. It's her dads ex, OP has already mentioned shes basically a stranger to DD.

What, that the kids don’t want to go this year? I think that’s where I would place my bet (and she’s taking the blame to protect them from hurting their dads feelings).

Not what she said.

@MissUltraViolet Sorry- I thought the 3 yos dad is second partner?

Then I would agree that DD doesn't go to ex house on Xmas day

Maybe because he is a human being with some empathy for his ex/mother of three of his children?

I think the very fact that he wants to take your dd shows that she is important to him as much as his other dc. He sees all three as his dc (as they are) and wants to see them together on Christmas day. This is why blended families and second families often struggle because the all parents involved don't all view all the dc in the same way.

I also don't agree he is prioritising his ex over you but after years of conflict he isn't suddenly going to be able to 'make' her agree to something. I have an ex and father to my dc who is unreliable and I can't suddenly magically make him stick to plans now. If a new partner expected that they would be within their rights to walk away but they wouldn't be able to insist I 'sorted it' as it's not that simple. You presumably knew what the set up with his ex was like when you had dd/decided to get married? You shouldn't have assumed it would change. I know that's pointless to say now but you have to accept that you are in a relationship with someone who has dc outside of your nuclear family and that will always impact you and dd in one way or another.

LoneStar7thats the real issue here isn't it.

I think lots of three year olds would be super excited to get to go see their siblings and show off a couple of their new toys.

Easy solution: do Christmas Day on Boxing Day. That's what I've been doing since my divorce when kids 3 and 6. They're 14 and 17 now. I also have a 4 yo with second husband.
Then next year it switches
It's not ideal but that's life.

So what if she’s raw? Why does that trump everyone else’s plans?

There’s no way this would be the suggestions if it was the DF who had just split up and was going to be alone.

What 3 year old is going to be happy being taken away from all of her new toys to go sit in a strangers house to watch her teenage brothers open gifts, come on now lol.

Tell DH go alone for an hour or two, deliver their gifts, spend some time with them. DD presumably can spend boxing day with her brothers if they are no longer coming to yours for Xmas day? Seems the best way to keep everyone as happy as possible.

I don't think OP is really having to compromise much or bend over backwards. Her DH and DC will be out for a couple of hours. They're hosting later that day so it'll be busy anyway and easier without a preschooler under foot. Or if all is in hand, how often does the mother of a 3yo get to sit down and watch a terrible Christmas movie in the middle of the day?

The DC going with the DH really doesn't have to be a drama.

AnneLovesGilbert I'd go to annoy her!!!