Don't Let Me Fall in Love

I'm dreaming of a girl I can't have. She's my tutor. My best friend's girl. And my weakness. But she wants to be with the golden boy, while I look more like the villain. Or at least I used to... Until I saw her smile for the first time. But a good guy, the one she wants, wouldn't desire his friend's girl. And a good guy she's dating definitely shouldn't be doing dirty deeds behind her back. So what am I supposed to do then?