Small party

[HeyJude]

I seriously think you are on the wrong page on this. It is not your sisters fault that she was invited and you weren't and neither do I think it's up to her to mention that to the organiser. If you really want to go then text the organiser and say it to them, otherwise just let it go. You seem determined to have a go at your sister and blame her for it, no matter what she does. TBH if I was invited to something that I wanted to go to then I would go. If someone was upset that they hadn't been invited then I would tell them to ask the organiser about it but I certainly wouldn't do it as it's not my place. If it's a 50th birthday celebration then everyone is big and old enough to figure it out for themselves. I'm not sure why you are still posting giving out about your sister when it is clearly not her fault or anything to do with her. If you really want to go then ring or text the organiser and say so. If they say you are still not invited then you need to move on.

[LucyS]

Surprise parties are a bit risky for so many reasons and this being one. Anyone who organises them particularly an overnight must be a fairly relaxed person and maybe that's another reason why they haven't thought through the potential politics of this situation

Agree.

It's one thing for a group of friends to organise a surprise gathering when it is just themselves. That is perfectly fine.

It's an entirely different matter when the surprise party is for nearest and dearest and the organiser takes it upon themselves to decide who is invited. I know I would not like it and I would be upset if a good friend was left out.

[DazedandConfused]

Might be an unpopular opinion but I always feel surprise parties are more about the person organizing them the recipient. Most people don’t like them

[janeymac]

I think some people just love the surprise thing. My dh's family all live abroad and they just love surprise events or if not, then their own attendance being a surprise.
I think the thing about parties and social meetings like holidays, half the fun is the anticipation.
With surprise parties and visits, you miss the looking forward to it part.

[chubbybumble]

It’s a night out. Rock up if you really want to (get on a plane etc etc) if not let it go.

As for your relationship with your sister that’s a different issue.

Based on how your feeling right now... focus on yourself