Very big backstory, but I have a sister who I find really hard work. She makes some seriously dubious choices and is massively hard headed. She turns spiteful if I disagree with her and her usual go-to insult is to say I'm mentally ill.
That's the condensed version.
Anyway, she has a new boyfriend who she is mad about. He is in the middle of a divorce and having a hell of a time with it all. But...the divorce came about because his exw found out he had been seeing a sex worker behind her back, so pretty much his fault, no matter how you dress it up. Since she's met him, they've set about trying to make things harder for the stbx wife in silly, petty ways, like messing up the house for when it's valued so he can buy it more cheaply from her. Sister routinely calls her a cunt (she's never met her) and things the sun shines out of her new bf's arse and sees him as a total victim.
What has annoyed me a lot is that when our brother split with his wife and then got together with an OW way too quickly (shit behaviour admittedly), sister was utterly vicious about it. Sided withe the exw wholeheartedly, refused to meet the new gf and this meant no Christmases together or anything. I got it! I just felt that she must have felt really strongly about fidelity and affairs. But even still, she was aggressive about it, not just dissaproving. I assumed she had a really strong moral view on it.
Anyway, now she wants to come to us for Christmas and bring the new bf. I don't especially want to host either of them. My opinion of her wasn't great to begin with (due to her nasty, aggressive behaviour towards me and other family members) and now it has dropped massively.
While it's lovely she wants to spend time with us, I find it really stressful as I never know if and when she might bite.
I'm having a stressful enough time of it with other personal stuff at the minute and I have young DCs. This request for me to host them just makes me feel more stressed!
Aibu to say no? They will be spending it together somewhere else if we don't host them. Neither of them will be alone.