Aibu to be hurt?

Awful way to make anyone feel OP.

Also as someone said their logic is skewed. Looks like they view your family as an extension of their family (minus you) and not as your own family unit.

I’d expect you’ve likely also been behind birthday, christmas, mother and father’s day gifts, cards and efforts. That can be another load off your shoulders. Even cards from kids, tell DP your circus 🎪 from now on.

It comes across like you’re not as keen on or close to your own family OP. I could have picked that up wrong?

Just wondering what elements of their family dynamic did you enjoy? That’s what you can replicate with your own but any way you can see your own clan more?

And that’s what makes it clear that you have a DP problem

Has there ever been any indication that they see themselves as different to you? Do they include you in other events such as family birthdays etc?

So your raising their first grandchild.

Biological mum to their second.

Yet you’re not family.

Yeah fuck that. DP needs to step and and speak out.

His version of love comes with boundaries as he is allowing his parents and siblings to put you in 'other' category.
'we are a family ' but you are not. You see your family as a unit but clearly your DP and the rest of them do not. They are deliberately excluding you, arranged this holiday without giving you a thought, presented it as a fait accompli, and your DP after initial push back is going along with it. That is not family.
My primary concern would be the effect on and the message it sends to your young impressionable 4 year old. His grandparents, uncle, aunt, his brother and his Dad are all going on holiday together and leaving Mum at home as she is not family. They are quite happy for her to be excluded and left at home.
It's cruel and disrespectful to you and it should have you re-evaluating your relationship with them, setting new boundaries and pulling right back. Yes, as your DPs siblings develop new relationships they may change their attitudes but meanwhile there is a young little boy along with his brother being shown that their mother/stepmother doesn't matter.

Are your partner’s siblings’ partners invited?

Do the family ever have meet ups of just siblings and grandchildren with no partners?

For the sake of adding one person to the holiday (you), you should be included.

To take your son away without you is wrong.

If it were a case of all siblings having short term partners then I might understand a bit better why they would do a blanket ban on partners but not in these circumstances.

If I were you I would use the time to go away myself either on my own or with a friend.

So you're married apparently =not part of the family. That means you can't holiday with them

Mil and fin are married so does that mean one of them are not family? So according to their own logic one of them should stay home .

"If it can’t be sorted, I certainly wouldn’t allow my son to be conditioned in this way to understand that his mum is so far less valued a family member that she isn’t good enough to be invited. It’s too psychologically messy for him, given you are still supposed to be in a relationship with his dad, and given that you are disappointed by the exclusion."

I found this paragraph very insightful. Kids see everything. They don't fully understand the nuance, but they take feelings about what's happened away with them. (Think how a dog understands human cues better than most humans). This will be so odd for him to be in a group from which you've been ostracized, and it'll stick with him.

I'm also wondering how your partner is going to explain it to him when he's asked, I'm sure he's not going to tell the truth.

@notpartofthefamily My Mil would never do this but more importantly my dh wouldn't allow it. What's wrong with all of them? I couldn't get over such a hurtful rejection.

A private conversation will give OP info to decide the nature and tone of the relationship going forward. And might even give some closure rather than the uncertainty of not knowing.

I think oP should pop round on her own and find out.

That is way too embarrassing and gives them more ammo.

If they’d of wanted to give an explanation they would have. Any put on spot conversation makes OP look pushy and desperate and they’re unlikely to give the real reason anyways.

Yes I'd be so hurt I'd be taking a step back from all events...I couldn't be somewhere where I know I'm not truly wanted....and when they asked where I wasn't there I'd make sure, like you said, that I'm not family so wouldn't want to impose!

No it wasn't. It's exactly what i had been thinking reading the thread. PILs had got close to Ss's mum, and perhaps just dont want to go there again. Perhaps they know their son is unreliable/flaky and they can't see this relationship lasting. Maybe they're just really horrible, but nothing OP has said so far indicates that. So there will be a reason. I think oP should pop round on her own and find out.

Sorry, but you're not as great as you think. A supportive and loving partner would not in any way think that this is acceptable! Blood relation or not, you should be classed as family and your partner should have your back and call this out for what it is - bullying! They are excluding you - which is a form of bullying. If your partner can't see this or call this behaviour out, then he's out of order.

Wow! I just cannot imagine inviting my son and grandchildren and not my DIl. No wonder you are so hurt. Sadly, it will change the relationship you have with them going forward and they only have their insensitivity to blame!