To think I did nothing wrong?

Are you 12?

She is being childish. Her reaction would actually really irritate me, rather than make me question if I’d done anything wrong.

I think you were fine. It sounds a bit like the other friend is still in school.

What etiquette is that?

Obviously, it's the longest-serving friend first, then alphabetical order of surname, then descending height order. Then if two people are exactly the same height, you have to draw straws.

Gosh, how have you survived not knowing this, OP??

6 years? I could sort of understand, maybe, if you'd been friends for 3 months.. But... even then, struggling as surely finding common interests is part of how you make new friends. So I could easily see a situation where friend A introduces me to B at a dinner, we all get chatting, have a great time and it turns out B is a huge fan of the same band as me and so me and B agree that as they're in town in a month's time, we'll go together... and so a new friendship is born.

This is why I hate set group friendships. I like individual friendships and vey very happy to do group activities, but resist anything that suggests only group activities as it's so hard to navigate if you just want to do something with one person.

I think friend is being a bit over-sensitive, but I can understand why. Understanding doesn't equate to agreeing with though.

Perhaps, to smooth her ruffled feathers, you could say something along the lines of "oh Ruffled, I am sorry if you were upset. I honestly didn't think you would mind, I knew you didn't particularly like The Bay City Rollers and I honestly thought the last thing you would want to do was spend time and money going to see them and be bored, and I knew you would feel too awkward about refusing. So I asked Missy instead because I know she does like them and I didn't want to go on my own. I am sorry if it upset you, that wasn't my intention" or similar.

I know you didn’t say op had done anything wrong just pointing out that they haven’t. Just because someone is upset, that’s not on OP, of course everyone is entitled to feel how they do but in this situation OP doesn’t have to feel bad for someone being upset

Just message her..
Omg friend you are 'insert her age here' not 12....
As you were.. Don't start pandering to such a ridiculous woman. You have not done anything..

You've done nothing wrong.
If you'd invited both of the others & not OG friend, I could see why she'd feel a bit left out but definitely not when it was a last minute thing with one mutual friend who actually likes the band.

She wasn't necessarily being unreasonable to feel how she feels - but she is unreasonable not to take a deep breath, realise she's acting like a 13yo and let it go.

I would get it if op had invited all the friends except original friend therefore excluding original friend from group but surely after 6 years it’s ok to have some individual time with another member of the friendship group who shares an interest that original friend doesn’t.

just because she’s a newer friend doesn’t make her not a friend even if O.F was the one to introduce them. It doesn’t make the original friendship any less important.

You're that friend.

You haven’t done anything wrong, but in the interest of peacekeeping I’d be tempted to say “oh I’m sorry you’re upset, I didn’t think you’d even want to go as you don’t like X band and friend obviously really does”

and then leave it at that, you haven’t got to apologise for taking other friend but you are acknowledging that og friend is feeling a bit sensitive over it all.
Ultimately this is her insecurity, not your behaviour

@Coconutter24 I didnt say that she had.

The OP didn’t know if the OG friend would want to go or not, I think that etiquette would say you ask your longest friend first especially as she introduced the other friends.

Just putting forward a point of view, no need for the pile on!

She doesn't even like the band? Why would she want to be invited? It would be like my friends inviting me to a bread tasting session (I'm gluten intolerant) I would actually be slightly hurt that they forgot how ill it makes me so maybe that isn't the best example 😅

I think you were not being unreasonable but it's also a little understandable if Original Friend is feeling a bit upset/left out. Nobody is in the wrong really, just a different view of the same situation. I'd just say sorry that she was upset and explain it wasn't your intention and you thought xx band was more New Friend's vibe than Original Friend's. Then I'd just carry on as you were really.

Sometimes people just need a bit of understanding and validation and then they'll go "oh, sorry, I was being a bit sensitive!". Only you know if Original Friend will take that attitude though. If she is the type to feel vindicated by the apology and become more controlling then I'd approach it differently. I'm assuming Original Friend is generally a nice, balanced person and this is a bit out of character.

Why on earth? Because 'YOU WERE MY FRIEND FIRST AND I GET FIRST DIBS ON TICKETS TO BANDS I DON'T EVEN WANT TO SEE'?

After six years??

That's unreasonable though. People can be friends with who they want. I have a group of friends and sometimes we do stuff without each other, my 2 best friends went to see strictly without inviting me, I don't watch strictly and they know I'd have no interest in going so it didn't bother me at all.

You did nothing wrong, but some people are weird like that and like to control everyone else's relationships with each other.

She has no ability to control your relationship with a mutual friend, and that lack of control clearly pisses her off.

She is being ridiculous if she is expecting you to adhere to some kind of friendship hierarchy which only exists in her head.

Even if you would be upset it still doesn’t mean OP has done anything wrong

Why?