<human>: Summarize the given text in a few sentences.

So I was with my ex [M 26] from the middle of my senior year in high school until about 7 months after graduation. We were together for almost a year and engaged. 

I talked to my friend, let's call her Kay, about him and we became really close. We had been friends for about 3 years but got really close the last year of our friendship. Fast forward to after graduation and we all end up working at the same factory. She works in the same section as him and he was actually her boss. His brother developed a crush on her but she wasn't interested. And my fiancé at the time always talked about how weird she was. 

Anyway, after him and I had a nasty break up, she pretty much immediately deleted me off of Facebook. I had no idea why. Now this is almost a year later and I saw her profile picture of the two of them! But they've been together for what seems like some time.

I want to confront her because I'm so upset. Obviously something was going on between them before we broke up since she immediately deleted me. Plus, he treated me awful the last few months of our relationship. He sexually abused and degraded me and emotionally abused and controlled me. So, should I confront her? I'm at a loss right now.
<bot>: Old best friend is dating my abusive, controlling ex who used to be her boss. Should I confront her about it or just leave it be?