I guess I could understand if they'd all grown up together and gone thru school together.  I guess.

But, this would seriously bother me, too.

They snubbed her and they knew what they were doing. If it was innocent they would have told her that they had to leave early as they were meeting a friend (if they wanted to avoid bringing up the ex). Perhaps they were trying to be sensitive but they just ended up being even more rude than if they'd told her about it and not invited her to join them.

I think I would mentally move all of them onto the list of people who I can't trust and who are more loyal to his ex than me. I'm not sure how I'd handle the next holiday gathering, it would depend on how they treat me in the intervening time I think. 

That is extremely rude, so my first reaction would be to avoid these people in the future. If that would create a lot of drama, I might consider going along (partially) with the advice above and remind these people that the purpose of the holiday gathering is to spend time with relatives and they should stay a while while after dinner--can they arrange their time with the ex either for earlier or much later (or another day)? There would probably be pushback, though . . . and there you'd have your drama. 

I don't know why so many people in our culture think it's ok to crap all over second (or third) wives. 

When things have gotten too complicated here with the holidays, we literally head for the hills--rent a cabin and say bye bye!  

I feel like it's fine for the wives to continue to have a relationship that stands on it's own with their brother's EX.  

I think they snuck off because they didn't want to make it obvious and thought it might hurt the LW's feelings.. which it somewhat has now that she knows.

I think given the treatment that has not been unkind prior to this that she should pretty much take the advice (though if there are several siblings.. it may be years before it rolls around to her again).  Let the wives know that if they have other people they want to see that day.. that they can let you know so that you can make sure there isn't too much conflict.

As an aside.. since you know that they are friendly with the ex.. these women are not suitable for you to share secrets.. vent to.. about the ex or your husband.. or anything really.  They have some loyalty to the ex.. it should be remembered.  Of course... as long as everyone is being nice.. no reason to shun them.

These people are not your friends, and if family you don't need them.  I would never invite them again to anything I do.  Or my family does birthday , party, events.   Make new friends, some people who are loyal to you.  This is a pit fall of second marriage.  Family and friends choose sides.  You know what side you are on.  
'real people whole of told you they were goning to BM to eat . 

That would be the last time I hosted a family feast. I would have been very angry and felt very insulted if they just all upped and left after the meal I had prepared. They treated your table and your home as if it were a restaurant,  OP. That is such a slap in the face! You were good enough to feed them but not spend any time with.

If they wanted to spend time with BM, then it was on them to set it up some other time, not to insult your hospitality.

If it were myself in that situation I wouldn't host them anymore. What they did was rude and insulting 

this article in WAPO and the majority of responses felt that, because OP didn't say she didn't have an affair that busted up the marriage, she obviously did. And if she did have an affair her poor treatment was completely deserved. 

I just don't buy that. I had nothing to do with my DH's divorce but because he was estranged from his children the assumption was that I did. I resent having to defend myself on that score.

And even if the husband did have an affair and then married his affair partner she doesn't deserve to be treated badly because of it. 

You missed the best part of the response, which was at the beginning.

"It was a spectacularly, thoughtlessly crappy thing for them to do to you.

I’m so sorry — both that all the wives weaseled on you en masse, when you were super-vulnerable as the post-divorce new spouse on the spot for a holiday feast, and that your husband didn’t immediately take the initiative to see that you were made whole once you figured out what had happened.

Anything short of an apology line snaking out your door was insufficient. Ideally in a downpour.

And … I’m not done yet … you can also think of it as a sad and, in a way, beautiful thing that was stupidly, needlessly botched."

Carolyn Hax definitely thought what they did was wrong. She is, however, a big believer in ex's getting along - so as she worked through her answer she did end up with those final words. (Her ex still illustrates her column.) Most of the responses I read were supportive of the OP, not the ex.

one of the members of a facebook group posted a link to this on Washington post. Of course, given the group, it was nearly 100% all about the fact that they believed with certainty that the OP was an affair partner.

Just because the "love" for the BM was so THERE. But we here know that the BM can be the worst person on the planet, and because she dropped a few DNA samples, there will be times that the family embraces her over the new wife.

Nope, that was coordinated Harpy Hag squad bullshit.  Purely designed to hurt the OP.  The SIL Harpy swarm could have done a side show trip to party with the brother's XW if they were not out to be toxic game players.

I hope that the OP's DH put his foot up all of their asses. Figuratively of course.

I would treat this for exactly what it is—a juvenile, high school-level power play. Do not, under any circumstances, react to these petty stunts. Why? Because that’s exactly what they want. By reacting, you’ll be playing right into the ex-wife’s hands, falling into the trap she’s so carefully laid.

You see, as the new addition to the family, you are a threat to her sense of relevance. The ex-wife isn’t truly important anymore—but she desperately wants to be. The only way she can cling to any relevance is by manipulating those around her, trying to make sure your husband’s family still acknowledges her presence. Through the actions of her little minions, she’s trying to send you a clear message: “Look, look! We like the ex-wife more than you!” or “See, she’s still as beloved and popular as ever!”

But here’s the truth: if she were really as relevant as she claims, she wouldn’t need to pull these childish games to prove it.I’ll tell you what the ex-wife and her minions did is very common.

When I married DH, the in-laws all flew into town to meet me. The ex-wife, ever the busybody, caught wind of it and decided to make her move. She contacted DH’s brother’s wife—my new sister-in-law—and arranged a little "catch-up" session. The kicker? My sister-in-law didn’t bother to tell me she was meeting with the ex. All she said was she was going to meet ‘an old work friend’. Liar.

After their little rendezvous, the ex-wife made sure YSD saw them together. Classic move, right? And of course, I’m sure YSD, under BM’s direction, made it a point to casually "inform" us of the meetup. Why? The reasons were crystal clear:

To stir up discord between my sister-in-law and me, planting seeds for a family rift.

To keep herself relevant in DH’s family.

To make me feel bad, insecure, or out of place.

To talk about me behind my back - my SIL ran to BM to report what I and DH have been doing. 

But here’s the thing—I ignored it. I refused to let them drag me into their childish games. However, I’ll never trust that sister-in-law again. She made her loyalties clear: they’re with the ex-wife. These women actually did me a favor. They showed me exactly who they are, and when someone reveals their true colors, believe them—and act accordingly.

One thing I’ve noticed about the so-called "First Wives’ Club"—they don’t like second wives. And here’s why: they fear that if they ever divorce their husbands, they’ll be left single and alone, while their exes will move on and find someone new. It’s the insecurity of knowing they might end up on the sidelines while life moves on without them.

Take DH’s ex-wife, for example. She strutted out of that marriage with her head held high, thinking the guy she cheated on him with was going to marry her. Turns out, life doesn’t always go the way these "first wives" expect.

After three years of separation, and a full year after the divorce, DH and I tied the knot just ten weeks after we started dating. Meanwhile, the ex-wife couldn’t find anyone willing to date her seriously. Sure, there were men who would sleep with her, but marriage? That was out of the question. DH and I, on the other hand, have been going strong ever since.

Second wives serve as a constant reminder to first wives of what happens when they lose their footing. If their marriage ends, their ex-husbands will likely move on, remarry, and find happiness again. But the ex-wives? They’re often left behind, stuck in the past. This is why first wives rarely get along with second or third wives—it’s not just jealousy; it’s fear of being replaced.

The first wives you are dealing with won't like you because of what you represent—that they if they divorce, can and will be replaced! Is this fair or logical? Of course not. People, most of the time, aren't fair, and they are not rational. 

Unfortunately, the 2nd Wives club can suffer with "He did that first with someone else!" - itis.  It is imperative that the new partners focus on the firsts they have together. Which is everything.  The first time, whatever it may be, is the first time the new partnership is doing those things.  Though each may have done that before with someone else, it is the "ours" first.

We see many examples of the 1st Wives club struggling for relevance and to dominate their X and the their new mate.  We see a number of examples of 2nd or subsequent Wives coming to STalk to vent that their DH had a kid with someone else first.  THis applies to DHs too.  Though less frequently in our community as DHs are notably rare in comparison to DWs here.

IMHO, the key is to recognize that each partner is the sum of their life experiences and that is what makes them the fit that they are in the new relationship.  Lamenting the pasts of each other, is a suboptimizing waste of time.

I would not change a thing about me or DW.  We each brought ourselves to the marriage with all that entails. We have built infinitely more together than either of us brought to our foundation. But all we have bult is on the foundation of who we were when we started.  Yes, baggage can be regrettable though it is part of the foundation of who we are in our partnerships.

That in second marriage there could be family problems.  The family could feel that BM was treated dirty by her ex and you.  That they don't want to end there relationship with BM.  
You can not control other people.  If they want to be friends with BM  then let them know you will not be part of this dysfunction.  They must choose. BM or you.  And you must adjust your life accordingly.  As no big family dinners. Let BM do it 

Take wife/ex wife out of the equation. Now it looks like the mean girls ditched the new girl. It's juvenile and rude.

If they want to see BM, fine. But pick another day.

Going forward, I would be polite but that's it. I'd really have to think hard about hosting again. 

the Harpy squad SILs. Make it a point to invite everyone else. Their DH's, kids, your MIL and FIL, etc... with clear exclusion of the Harpies.

Make sure it is done in a way that fosters full discussion with anyone and everyone so that the Harpy SILs are brought into the light on their crap.  Your DH is your IL's son and sibling.  If the SILs are his sisters, if I were DH, I would destroy them and stay on them for constant prennance and appogies for be. If they are DH's brother's spouses, same thing. I would make it a major point to keep these supposed family members on the hook for their bullshit baring their asses repeatedly to the entire family.

Just for clarifcation. Are the Harpy SIL's your DH's sisters, the wives of his brothers, or a blend?  The various answers to that question may provide for some reasonable forecast data on how each may respond.

In our marriage, my family would not piss on my XW if she were on fire.  My ILs would not waste the moisure to extinguish the flames if the same were the case for anyone in the SpermClan.  We do not have anything remotely simlar to deal with on either side of our X baggage history.

My assumption is that your DH is not the root cause in all of this and his XW is par for the course that so many have to deal with regarding toxicity.  However, the concept of the common denominator is a 50/50 thing as to whether DH is the source of the toxicity, or his XW is the source of the problems and toxicity.

You are the one with the view that can answer that question.  In your opinion, which is it?