Our first year together, DH went over to BM's house Christmas morning.  He didn't really discuss with me, I was blindsided.  I guess by the next year, the situation had changed enough that he didn't do it.

But, I totally understand how you feel.  Once Christmas, the worst week of the year for stepparents, imho, is over, I'd discuss calmly and let him know how upsetting it was to you.  You're not married yet, so keep your eyes open and judge for yourself if he has done the "work".  That's what the ST community calls it when a man has done the emotional work to create his own home, his status as a non-custodial parent, a person with his own life, ie, not still enmeshed with the former family's traditions.

Good luck and keep reading ST.

Wait, did i read that BM's boyfriend is going to be there? If so, you should be invited too, at the very (and i mean very) least!

I agree with the above, that your boyfriend has not "done the work." There should be no happy first family Christmases once the couple divorces IMO. It's like they couldn't commit to marriage and togetherness before, and now they can't commit to divorce and separate lives. A half-ass way to live, i think. 

Toxic people =  toxic milestones. My ex made the holidays all about his kids and his family members, which was fine but after awhile it would've been nice to at least get a one gift and spend some time with my family and friends as well. Everything was all about him, his kids, and his family, etc. However he did want to include me when he needed help paying for his kids gifts. It was entirely one sided. Holidays are a good indicator of your future and how much you are valued in the relationship. Little value = little respect and appreciation for you during holidays. 

Ive been in this situation before and ouch does it hurt!!!  and im sorry but it will most likely happen next year also and possibly year after that.  you have already given him permission that he can go,, that takes that side of stress away for him so the tone has been set now.  If the Bm's BF is there , why dont you go also ? (personally i wouldnt go want to go but still).  In my situation i wasnt invited and didnt find out till a couple of years later which made me feel so decieved and shat on.  Please dont get to this feeling, talk to him about it first and if you get resistance ,, exit stage left

I think the hardest part of steppin' is this weird dichotomy of what we understand as parents and what we feel as partners.

We can't control other people's behavior. But we can control our own. I've learned conceptually, and am trying to put into practice, that I need to be true to myself as much as I need to have empathy for my SO's parenting plight. 
 

when this happens for me, I tell my SO. For this instance, I would tell him- I fully understand your desire to be with your kids on Xmas. They are only little for so long. But on the other hand, as your partner I need you too. There isn't a clear solution, and I feel hurt, but I also feel unjustified about feeling hurt. (Sometimes just saying it helps, and it gives him space to swoop in and support you and sometimes that's all we want even if it isn't perfect-that connectedness is what you're wanting after all isn't it?) 
 

you're a good person for making the sacrifice you did, and I believe you do love him. At some level, we have to accept there isn't an easy straight forward answer, but that doesn't mean that there are not other ways to scratch that itch you're feeling in his absence. Maybe the question is-is there another way that you can feel connected with SO on Christmas and he can still have his skid time? 
 

think on it. You'll be surprised what you come up with. <3

Am I understanding that he will have the kids Christmas Day? If so, why in the world does he need to spend Christmas Eve with the kids and BM and the ex-in-laws? Do you have any sense of why BM is encouraging this? Does she still have a boyfriend? It seems odd she wants your SO to be there during her time with the kids.

I have to be honest, there is no way I would find this acceptable. It would be a hill to die on in my world.

When you said he wants to watch his kids open their gifts, please tell me he doesn't take his gifts over there too. Why can't he watch them open their gifts on Xmas day at your (plural) place?

This guy isn't ready to be in a relationship yet, he's not emotionally divorced - and you are being too accommodating. None of this is okay, and your feelings say you know that. Time to insist on some changes for your sanity. If he can't move on and adapt to not seeing his kids on every holiday, then he should not be talking about marrying someone else.  

I have no advice, but I ead your vent and wanted you to know I had. 

A similar situation happened the first Christmas with DH, and I plainly told him it wouldn't happen the second or I was out. FIL hosted Christmas before DH and I bought a house, and he didn't want any trouble with BM who got invited to spend Christmas with them. The second year, BM and I were both invited. The year after, I invited her to our house for Christmas, trying to keep peace. After that, though? BM gets Christmas Eve and DH gets Christmas.

Why does your SO need to be there? Does he not have his own gifts for the kids to unwrap on Christmas Day? And why can't you and your kids go with him? And does BM even really want him there, or does she just feel guilty and it's awkward for everyone?

You're right to be upset. You're right to question whether this will actually be a marriage or if you'll just be a surrogate partner who performs wifely duties without the wife status and respect. You SHOULD make your own traditions as a new family. New doesn't mean worse. You seem to get that, and you need to find out why your SO doesn't. It sounds like he hasn't done the work to actually divorce the first family structure, and he has to do that work so he can build a new family structure.

It sounds to me like your boyfriend hasn't extricated himself from his first family yet, and you are too accommodating. That combination is a recipe for hurt and resentment for you. I don't know how you undo that for this year, since you already gave him "permission" to go, but if you view this as a test of where you stand, he failed. I'd watch closely for other "failures" before making any commitments, and I'd start prioritizing my own needs, since he is not.

He had to know things had to change.  He should pick up his kids and take them to your house to spend time with them.  At 8 and 11 they will understand.  They understand there father is with another woman.   His idea of his old Happy Family is gone.

He has to create a new Happy Family with you.   He can not spend holidays with the ex.  That a Big Red Flag.   Next thing will be vacations with the ex .  You must put your foot down . Your are number one and he spends his time with you.  Not playing games 

But Ill reiterate. Hes still very enmeshed with his "first family".

Id really think about if this is what you want for your life. Not only are you going to be helping raise someone elses kids who are young when youve already launched (assuming) yours, but you are also going to be "pushing the rock uphill" getting him on board with being with YOU as a full-time fully engaged equity life partner.

New Year, new path.

I would back way off and just date the dude.

ALSO, I would suggest that you can tell him how you feel right now and, well, tell him youve changed your mind. I dont know if this is possible, that he can change his plans, but Ill bet you its more possible than you think. THEN if you do this and he still wants to go be with BM, you know where he stands.

It hurts, but sometimes you have to rip the bandaide off. 

It is not good for the kids - it will only confuse them and make them resentful to you.  He needs to understand that he is divorced and his family has to adjust.  That means he can't be there with his ex and in laws for Christmas or other holidays.  Maybe a quick hello during the kids drop off and pick up but that's it - no staying for opening of presents or food.  And no presents for the whole ex in-law fan damily either.

He can't start a new life partnership until he really lets go of his ex wife - that includes the 'happy family' image so the kids can also do the same.

Please rethink this relationship. I see you have thats the first step. The next step is the biggest...step away from a sickening step situation. I used to be you. Getting hurt because he would leave for the ex family, except in his heart he wanted them. I was married 10 years. IT GOT WORSE.

Its Christmas and you should be enjoying this with your BF. He does not need to see the rugrats at the ex MIL. He will see them christmas day. Those are excuses because he hasnt let go. He is showing you that when it comes to the first wife and kids you are invisible.

Is he worth the effort, the heartache?? 

Sometimes people have to make the same mistake multiple times to alter their behavior. Your boyfriend had a miserable time last year and will likely have a miserable time this year too. That is his natural consequence for his choice. Go and have a lovely Christmas yourself and let him see what his alternative Christmas could have been like. 

I have found over the years that there are certain topics that I know not to trust my husband's professions that he won't do a certain thing (again). 

These days I tell him how I feel about a thing, give him my advice, suggest alternatives but accept that he has to make his own decisions even when I don't like them. There is little point in blowing up over most things. 

There are not many things that are absolute deal breakers to me, but I do note his descions and back tracking of past proclaimations and am less trusting of his word on those types of topics in the future. 

You are not his priority and neither is his relationship with you.  You in all likelihood never will be.

Save yourself and put this weasel and his failed family in your rear view mirror.

I would definitely have a serious talk about how you feel with him before marriage. He needs to make traditions with his new family. I know it's sad when you can't be there with yours kids, but if he is doing this now he will continue once y'all are married. Let him know now it's not ok. I wish I would have done that with so many situations before I got married.