Boyfriend’s female best friend is a lil messy should I be concerned ?

My boyfriend has a female best friend. She’s super sweet and pretty. I have a pretty friendly relationship with her too but she’s really mmm a lil messy.

To begin she’s sleeping with my boyfriend’s older brother….who is also in a long-term relationship with a woman he’s considering proposing to. She knows that he’s in a relationship and has been around his girlfriend on multiple occasions because they all share the same friend group from undergrad. She’s also sleeping with another guy in their friend group who is actually in love with her and has no idea she’s messing around with his close friend/frat brother.

In addition, she has gotten drunk and invited my boyfriend along with his brother and one other guy she’s sleeping with over to her apartment at the same time. This happened twice- the first time my boyfriend stopped his brother from coming in because she was…unwell and the other man was in her bedroom already. The second time it happened my boyfriends brother walked in (at her invitation) on my bf’s best friend with another man naked in her bed. The naked guy was yet another one of their my bf and his brothers friends…not the same one mentioned above.

This isn’t the first or only time she’s dealt with men in relationships. Last year she was involved with a man who was in a long term relationship and she said something inappropriate about the man’s girlfriend and the man reacted violently (which I really hate for her because no woman deserves to be abused by a man..no matter what she says).

There are just so many examples of her being reckless and hooking up with men in relationships that it makes me question her character.

My boyfriend has also admitted that he finds her attractive and he’s much more upset with her for sleeping with his brother than he is at his own brother for cheating on his girlfriend with her which makes me question if he’s really mad because he’s jealous and maybe if he wanted to pursue his best friend romantically in the future, he wouldn’t be able to let go of the fact that she slept with his brother.

My bf and this girl hang out a lot usually at bars but sometimes he goes to her house (usually with other people) and vice versa and when they do hang out he tells me about it. Im not an insecure ass bitch but I don’t fully feel peace with that relationship and I’m trying to establish boundaries which he generally respects.

But I just wanted to know. How would y’all react if you were in my situation? Am I being insecure ? Below is a recent convo between me and my bf that shows I’m not responding aggressively to this, but I am concerned.