Hey Ah,
All this is going to be my point of view, and probably not my most cohesive writing but I hope you'll get what I'm trying to get across
My opinion of things is formed only with the info I have, so it won't be perfect but just decide what you can use and ignore the rest okay? Just take it in consideration and know it is coming from someone who really cares about getting you through this and helping you forward.
Above all, listen to yourself.. I respect you for what I've seen from you so far. I realize that your situation is probably a lot more complicated than I know.. That said, I also have a lot more distance to your situation, so here's my opinion, and my warmest deepest wishes for you..
Here is what I would (want myself to) do:
I agree with pretty much all of the things said above.
I also think you should tell your third party that you have had a problem in the past with the people they invited.
Don't go into detail, but make it very clear that these particular people are NOT welcome.
Mentioning the issue opens the door for other people who may have had, or have, trouble with these same people.
Silence only keeps people thinking they are all alone. Chances are you are NOT the only one tip toeing around these people. Not the only one staying quiet.
Don't don't don't go into detail to the third party (tempting as that might be), this isn't about your personal experience, it's about about not keeping quiet and taking it.
Too often once one person speaks up, others come forward.
Don't get drawn into any arguments about sides of stories, or feed curiousity at your own expense, but don't stay quiet.
Tell your third party you have a history with these people and that you don't feel comfortable with being around them. That it creates a ton of anxiety for you.
Be honest about how *you feel*.
Then tell them to un-invite them. If that isn't possible, reschedule with the person you wanted to meet. Same day, same time, somewhere else. Yes, you can tell them why. Same as 3rd party mentioned earlier, talk about how *you* feel. Stay close to yourself. Then figure out the most fun place you could spend some time together that doesn't strain whatever budget you may or may not have. A local library would work.
If you were going to meet at your home, and you just can't go elsewhere, do NOT let the people from your past into *your* house. It is *YOURS* and you alone gets to choose who is welcome! No matter who else invited them, you DIDN'T. Make sure you made this clear to ypur third party, and have THAT person uninvite your uninvited guests. You didn't invite them. It is NOT your job to uninvite them.
Should they show up, take a really deep breath, and tell them in a clear voice "I'm sorry. I didn't invite you. Please leave." No matter what they say or do, repeat this one more time, very clearly, the call the cops to escort them elsewhere.
Don't go into what they did, or why they might have done that to your friends/guests. Just be very clear that you have a history with them, and that you do not feel safe and comfortable around them.
In other words try not to talk from the perspective of your abusers. Stay close to *your own* emotions. Do the opposite of dissociating. Tell them how you feel.
If the answer is a confused mess of nerves that you have trouble even finding words for, then say that. It's plenty good enough.
It isn't about specifics in history.. everyone has felt like a ragged emotional mess before. Everyone.
Tip: The people you should keep in your life and company are those that will accept this, whether you are close or not, because they *care* about you. The warmth of response to you asserting yourself, and being open about being vulnerable, should give you a big hint in how much energy you should spend on particular people. Trust your own instincts in this, and consider keeping those that take issue with you speaking up a bit more at arms lenght.
You have the right to meet whoever you want in a place and way that makes you feel not only secure, but comfortable and happy.
So why speak up that you have a history with them if you're not going to talk about what exactly happened??
Not only does it send a warning that there has been an issue in the past, you're also not willing to gossip, or argue about what did and didn't happen etc. Your feelings are not up for debate, nor subject to majority vote.
(this is why it is so important not to fall into the particular trap of going into details, talk about how-you-feel.)..
More importantly: it helps others speak out as well, and what they say or don't say will have anything to do with what you have said, because you only made very clear about how you feel about what happened to you, and not the specifics.
It will make anyone elses experiences (and your own) a lot stronger if and when someone else does speak out while opening a door to do so.
Well meaning as it might have been of your third party, *you* invited someone *you* wanted to meet, and NOT the other people.
Your meeting. Your terms. Period.
I know how very hard it is to he assertive, God, I know.. but I honestly feel this is where you need to draw the line.
Don't let this be brushed off. Don't let anyone brush YOU off on this.. please..
People who *care* about you will respect you all the more for it. Whether they completely understand your point of view or not.
More importantly.. as hard as all this is for people like us, saying "no" instead of just dealing with the aftermath again and again, I think this will also help *you*.
It's hard to be assertive, but listen.. you *survived* this. You might feel like they "beat" you, but you survived.
And here you are looking for a way to handle facing them again! You are a survivor, and brave enough to ask for help when you feel you need it. Don't dismiss that, okay?
Your emotions *aren't* your enemy. They are telling you something.. I think you should listen. I think they are saying that you shouldn't do this, but in the end you know "you" a lot better than anyone else.. and I think you should listen above all else to yourself.
Dissociation is about getting away from our own "self", and about not listening to yourself in order to survive something extreme. You survived it. Well done! All of you helped you do that.. so start listening to all of yourself again, okay??
*biggest hug in history of big hugs*
Lexx (who is trying very hard to follow that advise as well... sometimes even successfully

)
P.S. have some extra treat on hand for yourself for after, no matter what you decide to do.. You've earned them.