This isn't right. He definitely shouldn't be doing this. She's his best friend's younger sister. He shouldn't be, but she's always had a crush on him and wanted to learn. Her brother always made a point of having a no dating policy for his sister; none of his friends were to have her; she was off limits. And he shouldn't be teaching this, as he has no experience for himself. But he gives her what she wants. "So beautiful, my princess." He loves her.