<human>: My boyfriend of 2yrs, let's call him Sam, and his best friend, let's call him Nico, moved in together a good while ago, and I kind of came along as ''a part of the package'' (I'm here up to 4 days a week). This has all been working out fine until Nico got in a relationship with a girl that also stays here for the majority of the time. Me and her don't really get along, because honestly she annoys the shit out of me (babytalk, a lot of screaming, random comments, typical hyper pre-teen behavior etc) and she's violent and inconsiderate towards Nico (She makes a scene _literary_ EVERY F'ING TIME we're out or got friends over. Last time we went out she poured beer over him and hit him for not getting enough attention, then stood outside of the bar crying to the guard until he came out and went home with her).

So yeah, I'm having this Halloween party this year, and I've invited all my friends and all of me and Sam's common friends. The main problem is that he want's Nico to come, but I'd have to invite his GF as well and I just really don't want her at a) my party and b) in my home.

My home means a lot to me and my family, and we've always been quite strict and forward when it comes to people we don't like. I feel like my home should be a place I want to spend time with people I like and care about, and where I can relax without stressing about when someone's gonna flip out / make a scene. There's like a 70% chance that she'll behave, but even still I feel uncomfortable letting her come. Even when she's on her best behavior I really don't like her.

What should I do?

Could you distill the essence of the text into 1-3 sentences?
<bot>: My boyfriend wants me to invite his flatmate to my party, but his GF is crazy. Should I invite them?