Rules For Thee But Not For Me

Long story short I was in a poly relationship (3 of us) that turned into a hinge, which then turned into me just becoming a roommate. My "ex" girlfriend still loves me and wants to be friends, wants to spend time together, and I'm all about that! She's great! But her SO is being unreasonable in both of our eyes. Her SO is notorious for throwing fits when they don't get their way or if you don't respond right to something they did, but if you do something similar or act the same way suddenly you're the bad guy (It's her way or no way).

A couple years ago her SO begged and pleaded to be friends with this older man from her job, my girl caved eventually and agreed which then lead to her being cheated on. She still allows her SO to see this friend and he even takes naked pictures of the SO. Cut to now I'm in the process of moving and her SO won't even allow her to help me with small tasks, won't even let her come see my new apartment or even hangout with me outside of work! My girl asks permission to just be around me everytime and is always told no. Her SO says "It hurts me when you keep asking even though you know how I feel" which is EXACTLY what my girl told her SO when they begged to be friends with a married man.

In short I think her SO is being extremely emotionally abusive towards her: cutting her off from friends, making her anxious about every little decision, everything she does HAS to include the SO, etc. I just don't know what to do and neither does she because her SO is prone to not so great coping methods, so she feels really stuck... If I even attempt to say something remotely like this to the SO I know it's going to result in a fight. AGAIN. And I'm really sick of being the one seen as the bad guy when I'm trying to defend my sweet girl...

I dont care if you give advice, if you judge, whatever, I just needed to get this off my chest because I have no one else to talk to about this.

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TL;DR - Emotionally controlling SO says rules for thee but not for me and if you say otherwise you're the asshole.