This guy confuses me! Help? I need to understand this.?

This guy is my brother's best friend, and I really, really like him. He calls me ........'s sister. (..... is my brother's name) even though this guy knows my real name. He does it every time he sees me, like in the hallways at school, or when he comes over. He always just yells "........'s sister!" and he looks at me with his sexy blue eyes. He also flirts with me, even though he says he won't go out with me because I am .........'s sister and younger than him. Yet he still flirts with me, and I was texting him behind my brother's back one night and he was acting all sweet and innocent. So do you think this guy likes me? It's not a lot of evidence, but just give me your advice/opinion, please?