Partner in massive victim position giving me the 'ick

Have you ever tried actually being understanding though instead of reacting in anger? You'll be doing her self esteem no favours by making her feel like an idiot for feeling rejected or left out.

Not going to lie, she sounds a pain in the arse. Let her miss the beer festival, you’ll probably enjoy it more without her. I can’t do with adult-children who strop and take offence at the slightest perceived slight.

But why are YOU triggered?

So he's now added her then if it was just an oversight? Mistakes happen, your op made it sound like it's a regular thing and not a one off.

I get you OP. I had a friend like this. Has to be directly personally invited to things, anything which goes on even if it's something she only has a passing connection to or wouldn't even want to do.. or else it's 'people are actively excluding me' 'no one likes me, everyone let's you down'
She was like a 10yo in a school playground. I did have sympathy at first because I know it must stem from insecurity due to however she grew up.. maybe she was bullied or had some other types of difficulties in childhood.. but I think as an adult you do have to at some point start taking responsibility for yourself and not just constantly be 'woe is me' 'everyone let's me down and stabs me in the back'
Because people who are still acting like that as adults become massive energy vampires and live a self fulfilling prophecy. No one really wants to be around someone who is convinced everyone else is a bad person who doesn't really like them and will let them down. It's a feedback loop.
I had to stop being friends with my friend in the end because I couldn't handle the relentless negativity and paranoia. I did give this friendship 15 years BTW.. it wasn't like I just cast her aside.. but it got to the point where it was effecting my mental health. It was like walking on eggshells. Every interaction was awful and gave me major anxiety.. I was constantly worried she'd feel rejected or slighted in some way. Coz if there was a way to take offense shed find it.

I think all you can do here is try to listen to your gfs concerns attentively without immediately dismissing them. Provide some reassurance that she is wanted and loved...
However at the end of the day if you are consistently doing that but find you are constantly having to 'prove' you care about her because she will never believe it.. perhaps it's time to end the relationship. Obviously the healing journey she needs to go on is not happening with you if she's blaming everyone else rather than how she feels about herself.

She's got a victim mentality and you've been triggered... good golly gosh what a pair you both make.

Ok so maybe validate how she's feeling a bit? Maybe if she does consider these people friends now she's just upset at not being included. Does being 38 mean she can't feel left out?

Maybe there's a reason she got no friends.
Too much drama

Can't you add her to the beer festival chat?

So you're planning something to attend as a group and a WhatsApp chat made to plan this, but your new friend has added only three of the four people going? I can see why she feels left out if you're all supposed to be friends with each other and going together. Personally I'd wether ask for the fourth person to be added as it makes things much easier and I'd say that wether it was my girlfriend or just someone else.

The fact she suggested the local beer thing for you do instead of theatre kind of makes it sound like going was her idea in the first place and now she's not part of the planning?

It's hard to tell what you meant in your OP though

Even with his updates it's impossible to work out what he's annoyed about.

Your OP is a bit confusing.

Are you saying you were going to go to the theatre but your girlfriend realised the dates clashed with a local beer thing?

It sounds like beer thing is something for you all to go to as a couple of couples at least, if so then yeah, it's a bit odd if your friend has added his own girlfriend to the group chat to plan the beer thing if it's something your girlfriend is going to too, why not add everyone to group chat who is going?

Group planning when some of the group participants aren't even in the group chat can be stressful and take ages, because it needs someone to contact people who haven't been added to group chat and report back to the chat, also gives room for miscommunication when at least if all people going can see all the messages and are part of planning, less mix ups can happen.

Much easier to chose to have everyone attending in the same chat and she probably thinks because he chose not to add her, then him or his girlfriend don't want her to go, is there a reason you can't ask for her to be added? I can see her point of other girlfriends and partners are involved in the planning.

If your mates partner and your girlfriend aren't going to the beer thing, then none of them need to be in on the chat and I'd kind of think if my friend started a group chat to plan something and added her partner who wasn't coming, I'd find that odd too to be honest.

It's hard to tell what you meant in your OP though.

That’s sweet of you. But don’t get furious - ask her why she’s so moody about the WhatsApp.

Tell her you’re not in charge of other people’s brain cells. If she doesn’t get it or tries to blame you again, LTB.

I hope you're clearer in real life than you are on here.

I still have no idea what you're talking about.

So why did you mention them?
🤣🤣🤣

I don't really follow, but what leaps out is: you think she "pulls crap", you "literally can't handle it" and get "really really angry". I don't know why you react so strongly to the things you describe, but for her sake I don't think the two of you should be together. Leave her be, and then spend all the time you want trying to understand your reactions if you want to.

You feel ‘punched in the gut’. That’s not a proportionate reaction.

Unless she hit you.