I'm sorry you're feeling hurt attn..... I understand where he's coming from though in regards to his daughter... The two of you have only been together a short time so I don't know how well his daughter knows you yet?
It seems that he's putting his daughter first and that's good for your daughter as well that he thinks so highly of the well being of children first and foremost.... He sounds like a really good guy
I hope you have a good Christmas day tomorrow

Sounds like a huge red flag to me. He was hiding this from you. He's spending a holiday with another woman, a woman who isn't this child's mother. Most people would consider this cheating. He clearly knows this is wrong, which is why he was hiding it. I don't think it has anything to do with his daughter. This is not the child's mother, so that makes no sense. To just randomly celebrate a holiday with an ex... no. big red flag. Reminds me a lot of the last guy I dated who said the same type of stuff that this guy is telling you. I believed him the entire time, gave him the benefit of the doubt, and after a year found out all the massive secrets he'd been hiding all along, including cheating.

I think the holidays put all kinds of heightened expectations on things, and not necessarily in.a good way. Emotions run high; feelings get hurt. Did he lead you to believe he was going to be spending christmas eve with you and then changed his mind, or did you assume you would be together, without discussing plans?

How old is your daughter and his sons?

Sorry I didn't read this correctly... I agree that there is no reason to be with his ex wife and not have you included if it isn't 'their' daughter.... I have always been close to my ex SIL and always will be though...
The only thing that I see that he may want to wait for is to make sure a newer relationship is on solid ground before getting to know his child (if you don't already know her)

He & the Ex have sons together.. he has a 4 yr old daughter.. he wants all of his kids together. You are a girlfriend correct? Ring on finger, moved in yet? No? Then you need to be patient... next year if you are still together and he does the same, then it is time to be irritated. Good luck with your new relationship.. it's going to be hard, kids from different mothers...

Thanks everyone for your feedback. I think it was a little about what all of you said - mostly about the kids (daughter being with her brothers, sons used to being with their mom and him as he hasn't been in a relationship in a long time, and our relationship being fairly new and he said next year we could plan ours, etc.). However, there's another issue here...

Christmas day came, and he said he would text me upon dropping off his daughter, so with a ton of things to do, I planned my time around this as I figured I would have about an hour to get here after that, thinking he had to go home first etc. Well, he texted first when 10 mins away, then again 2 mins, and I was "yikes, I'm still in my pajamas, no make up." etc. I was getting stuff done, but just not ready for him yet. But told him he could still come over, I just would have stuff to do while he was here. Well, he turned around and went back to the town where he dropped off his daughter (1/2 hr away), which wasn't necessary, however, wanted to give me more time. He said he would stop by a friend's quickly, and we agreed that he would come by after that. Hours roll by and I didn't hear anything, then I texted, a little later called and no answer, a few more texts and calls to let him know dinner would be ready soon and my daughter would be home soon...but nothing. Didn't hear from him for the rest of the day at all. Spent Christmas day without him.

The next morning he texts saying he got drunk (he doesn't drink much) at his friend's, and drove home at 4am after waking up and so on, and in another text apologized. He's never done anything like this before, but I think it's a pretty big deal to miss your Christmas with your significant other. I haven't talked to him since. The only thing I feel he has going for him here is that he tried to come over initially and gave me more time. Otherwise, I think it's pretty crappy and haven't wanted much to do with him. Could any of you get over something like this? Is this something you get over?

Outside of it being Christmas, it's an inconsiderate and disrespectful thing he did. What adult man knows he has plans, and instead chooses to get shit faced at a friend's house instead and then is all oops sorry the next day?? Listen, most people can get over anything; it's about if you want to get over it, if you want to move on. If you give him another chance, you just have to tell him how unacceptable it is to leave you hanging like that, and that you'll not tolerate it again, and mean it. But honestly, he sounds like a clown though. I mean, I actually thought the situation with his kids was understandable. But blowing off the plans you had together, especially if he'd been in contact with you earlier and was almost at your house already, something is weird about that. If I were you, I'd seriously question whether he was really that interested in having a relationship with me.

Unfortunately, this is what it is like to date someone who has 3 kids by different people.
I understand why you feel hurt and it truly does, but the children are small, they don't understand everything yet and it gives them a lot of security to have their parents together during a holiday season, this has to come first.
He also offered to spend the next day with you. I think it was wrong of you to fight with him about it.
I would be upset as well, but not let him know because the right thing is the right thing and my feelings have to take the back seat on this one...
hugs