Is AUTHOR wrong in the post ? POST : So there is a lot of context here and back story but I really want people to be well informed so sorry for the long post. 

My twin sister is kind if a nightmare. I love her dearly and she is my best friend but she is the most self absorbed person I have ever met.

 During our teens she was beyond horrible to me but that's a very long story. Most of this stuff I brushed off because at the time she was undiagnosed and therefore unmedicated, for bipolar disorder. The trouble was though that as soon as my family found out it became 'don't make her upset. Just do what she wants.' And this set a bad habit for the future.

Then I met my husband and moved out. By now we were both adults and despite still being a spoiled bitch, she had calmed down a lot and had become happier, funnier,  and usually an honest delight to be around. We were finally best friends like I had always wanted. 

Now my sister has no close friends at all and cycles from one majorly abusive relationship to the next. (The most recent being a violent drug dealer with gang ties who would hit her, steal her money, and cheat on her). Because of her lack of healthy relationships she really clings to me and is super protective.

She HATES my husband and uses any chance she can to talk shit about him. She even tried to figuratively blow up our wedding (that's a way longer story) and has been trying to get me to divorce my husband ever since all because "he's a selfish asshole".

Now to be fair my husband has admitted her is both selfish and that most people think he is an asshole. He is sarcastic, very guarded,  sometimes rude, but he is also funny, sweet, caring, a hard worker, so loving and just so much more. I love him so damn much.

It's frustrating to me because she can tear my husband down all while dating and angrily defending the absolutely horrible men she goes for.

My husband has and would never cheat, be abusive in any way. Sure you can argue he is an asshole but he isn't anything compared to these guys. But now that we have moved to another city he is the horrible man who stole her sister.

It's reached a point where I feel like my heart is absolutely being torn in half. I know my husband doesn't like her either but usually he keeps it to himself. That's all I have asked of her and she can't even do that. I don't feel like I can live with this amount of toxicity anymore, it's having horrible impacts of my physical and metal health.

WIBTA to cut contact with her completely?