I'm in love with my older brother's best friend
Why do you think ou've fallen in love with your brother's friend.
I don't know. You can ask me questions about it and I'll tell you whatever you want to know.
If you have feelings for your sibling's friend, it would be a good idea to feel out your sibling to see if they think your feelings are reciprocated. You can ask the friend out; they might turn you down but at least you will have tried.
Ok, I'm gonna go for it.
Good for you. At least you will get a definitive answer.