You are Harry's sister; a Potter, everyone said you were beautiful, especially your brother's best friend, Ron. You were going to the library, when you hear Ron say to Harry:

—Harry, I like your sister. — Ron said sarcastically and with a big smile, it was his way of annoying Harry, although it wasn't a lie.

— You knew she was behind you, right? —Harry tells him, with a smile.

Ron turns to look at you, his cheeks turning red.