Well, girl, fuck him then, because then you can get married and be a part of your best friend's life forever, because you'll now be sister-in-laws. Yeah!

Typical girl behavior.

hey girl you have a crush on your best friend's brother let me tell you something I used to like my best friend's brother before he had a girlfriend he told me I don't like you I was so sad that day

all i gotta say is what's gonna happen when things go wrong let's say the brother says yeah like i like you too and then let's say you break up and now it's like it's gonna be awkward for your friend um if you guys break up and then it's like you can never go to her house because you're always gonna be thinking your brother low-key you might not even want to talk to your friend anymore because she's defending her brother because it's her brother you know what i mean it's just messy okay like unless you're locked in for life sure even then how is your friend gonna feel about it what if she thinks you're only friends with her just so you can get to her brother it's just it's just messy

so first of all you should ask if your sister's brother is single and then you should ask if she wouldn't have any problem with you dating him because it would not affect your friendship you can allocate time between your friendship and you're dating her brother it's like any regular person does and that if you guys break up you promise not to make it a big thing because you know it's a family thing