AIBU to think step siblings can be evening guests only at wedding?

And yes the best advice is to stay out of it.

can be so very complicated. I had an invite years ago to a half siblings wedding, only myself not my partner or my DC. I didn’t attend as I wanted half siblings mum to have a lovely day it was her special day (she doesn’t like me). But for the same wedding one of my other full siblings wasn’t invited and another full sibling was invited with their partner. So weddings and families are so complex I would just stay clear.

I have full siblings, half siblings and did have step siblings. I’d only invite full siblings.

Aw that's good.

It does sound like there may not have been that much overlap between bride and the step-siblings, so hopefully they're all chill with it.

yes they should be invited to ceremony. There’s only 3 not 30🤷‍♀️

Or equally likely not.

I gained step siblings as an adult. 5 years later my Mum died. I still see her husband on occasion, but I haven't seen my "step brothers" in a good 5 years or so.

So what? My younger brother and I have nothing to do with our actual brother.

How do you know that? OPs friend got divorced once already. She and new husband might divorce. My step dad had two adult children, I met them about 10 times. They're fine. Stepdad died quite soon after marrying my mum, are those two adults who were my mum's adult step-children for about 3 years my siblings? On par with my brothers and sister who I lived with for 18 years and have known for 40?⁷

I really don’t share that view. I think if your oarent meets someone new when you are already an adult you don’t create a step family. My mum met someones when I was 20. My siblings were all adults too. 27 years later none of us view him as our step dad or his kids as our step siblings. He’s just mum’s partner and his kids.

Definitely do not get involved. Not your monies not your circus.

We are bystanders to brother in laws blended family. The knots that people have tied themselves to welcome, not offend, create memories. It's so painful for the young adults and the younger family. We do a lot of nodding and smiling and then repeat the flimsy family bonding anecdote of adult 1 said child 4 had a great hat as that was the only interaction all afternoon.

Wasn't even invited to my step brothers wedding. No problem here, were not close

I agree with this.

Your friend can’t force her daughter to think of her husbands children as siblings just because she married their dad. I have never considered the children of my parents new partners to be my family/siblings. I wasn’t brought up with them and don’t even particularly like most of them. I only had people I was close to at my wedding so only one of my mums partners kids was invited as we are good friends.

Parents and their partners need to stop pushing their children on to each other.

It sounds like a similar set up to what I had with my step siblings - dad and step mum married once I was at university, slightly younger step siblings. I get on well with my step siblings when I see them, but we’re not close. If it were a bigger wedding I think it would be a snub, but a small crowd like that I don’t see it as a problem at all - my step brother has done similar and I wasn’t remotely offended by not being there.

Don't get involved. You are 100% correct OP but it is not always necessary to be right and to win arguments - this is not your battle to fight.

They may also have good relationships with each other that are just distant. The bride was 19 when they all met. With both sets having another parental household to spend time in, the bride presumably having lived independently for a while and maybe from the time they met if she was at uni, it's possible there genuinely hasn't been that much overlap. In which case being on friendly but not close terms arguably would constitute a good relationship for the circumstances.

Thing is oarenfs can want things all they like but they can’t force their kids to feel like a family. And why would they?

I think once you’re had your “first” family - ie your children with one partner - it’s never going to be the perfect happy family you envisage with no complications. Some blended are happy, yes, but it will never be simple or easy. Adults need to stop thinking they’re somehow owed happily ever after.

It’s fine to invite people who are a mere duty invite to the evening yes.

I bet the step siblings don’t even see each other as step siblings more there dad wife’s kids and that’s mums husbands kids.

I've got step siblings on both sides. This wouldn't be an issue in our family set up.

I’ve got full, half, step and adopted sibs and I know exactly what each of them means to me. It’s absolutely no one’s business to call them anything other than my brothers and sisters, unless I’m doing a family history deep dive. It’s no one’s business to judge how long they’ve been in my life and how close in proximity we lived and I decide which invitations they get. I can’t believe people are getting so involved.

I guess if it was my daughter or step daughter doing this, I would be disappointed. But that is assuming they had good relationships with each other. I know nothing about your friend’s family.

In such a small wedding, sounds fine. Probably inevitable your friend would be upset because it's undeniable evidence that her DCs relationships with their step siblings aren't what she would wish them to be. But it will have done her good to hear the other side. I hope she's not going to be a dick about it.

Unreasonable, I think. They may ‘only’ be step-siblings in recent history, but they’ll be step-siblings for the rest of their lives.