one

The younger sister of Sirius Black, twin of Regulus Black, Aurora Black has always been in love with her older brother's best friend Remus Lupin. He liked her too. They never acted upon their feelings until after James and Lily were killed and Sirius was the one arrested for betraying them.

I don't own any of the characters except Aurora Black.

Friends to lovers
Brothers best friend

Kinda fast paced