Long story but trying to incorporate everyhing, please bear with me.
I am from overseas, my family stayed there, I am in the UK. My parents are divorced, it was nasty, but nowadays they can at least talk and make things work most of the time, my dad re-married (to the OW).
My younger sister (16) took ballroom dancing classes with her boyfriend and yesterday was the ball to commemorate the end of their course, which sort of was a big deal. My dad paid the course so he would come. I don't know if my parents talked about it but my mum wouldn't go, which I understand as my parents don't have a "let's spend an entire night in a fancy hotel and waltz"-relationship. My dad decided to invite his new wife as his partner. My sister told me about it a few weeks ago, she was kinda uncomfortable with it because we don't really have a relationship with her and that ball is a family affair and also because mother would go ballistic if she knew. At the same time she didn't want to offend my father, so I offered her a solution. I would fly back home over the weekend and be there for the ball instead of dad's wife so she wouldn't have to say "I don't want her there" ao nobody would be offended. She was really grateful but ultimately decided against it, instead just not telling my mum that the OW was coming and hoping she wouldn't find out. I said "fine, but if it all blows up, you keep me out of it" which she agreed to.
Of course my mother found out and was even angrier because my sister lied to her. Yesterday I was out with a friend to celebrate her birthday when all hell broke loose.
First my sister texted me something along the lines "Help! She found out and is mad at me" to which I replied "I told you so" and reminded her that I offered her help before but she decided to do it her way. She then started to have a go on me because "Why can't I have one night without being criticized etc", because I wouldn't help her and she was offended when I reminded her that it was her ball after all.
Almost the same time my mother texted me, angry, demanding I'd call her on the spot. When I explained to her that I couldn't as I was out with a friend she got angry with me as well. She has a form of dumping all her emotional baggage with me, despite me telling her that it makes me feel uncomfortable.
I have just talked to my grandma on the phone, my mum has apparently cancelled all the celebrations concerning my sister's graduation later in summer, she also has a form for overreacting like this
AIBU to be
...angry at my sister for expecting me to fix this?
...at my mother who thinks I am her therapist and always readily available?
... a bit angry at my father as well as he most certainly knows that his decision was a rather insensitive one?
Any ideas on how to deal with them? I am so sick of their drama but I can't go NC with them as I'll eventually have to move back home