Last weekend my younger brother introduced me to 2 of his friends who are a couple and we went out together. They have been together for 1.5 years, but he told me later that their relationship is very unstable and that she wants to break up, which is nice because the girl is gorgeous, smart and just my type. I could sense that her boyfriend is a very passive (whatever you like, honey type of guy..) and my smv is objectively higher, both physically and game-wise. I had an interesting talk with both of them during the night and she showed light IOIs. I know that one night of just talking with some dude won't make her throw a 1.5 year relationship away just like that, so if i add her and start flirting with her on instagram knowing that she is taken, will that be considered a dick move by my side, especially after i befriended her boyfriend? Maybe i should ask my brother to arrange another group meeting and only then escalate more? I don't know how to make that go smooth so i need some advice.