Did I overreact to his relationship with his sister in law?

My boyfriend of over a year and I just broke up a couple weeks ago. I couldnt have put into words how great he was. We had no big issues ( except for one huge sister in law problem) until the last week of the relationship. His brothers wife, throughout our relationship, continuously called him. She lives in FL so I only met her once but when I did it wasn’t good. She was very rude to me, rolled her eyes when I spoke, and would continuously put her arm on my boyfriend and look at me. His mother noticed the interaction which happened early on in the dating. He said it didnt matter to him if his sister in law and I weren’t going to be friends and he supported me. However, I heard almost weekly things about her and he occassionally would say how beautiful she was. I took it as she was his ideal girl. Her behavior got more demanding-she called him when we were on vacation together and threw a huge tantrum when he didn’t call her back until we came home. I found out by mistake through his phone that she had been trying to find him a place to live near her. Sometimes I would confront him about these things-he would either defend her aggressively or admit to some things such as she one time came out in only her underwear when he was over and another time told her brother how she found my boyfriend more attractive. Her husband seems to be mesmerized by her and doesnt care. I found this all very disturbing and in my last fight with my boyfriend he told me the fact that she and I would never be friends impacted how he thought of me and how he viewed the relationship. That ended it. He hates me because I told him I found his relationship with his sister in law bizarre. Any thoughts on this?