Love might be a choice, but some choices are off limits. They say opposites attract-and I'm not going to disagree. In fact, I'd be doing my best to see if the attraction was mutual if not for one little thing. She's my best friend's little sister. And since she and her brother are close, she's become the honorary sister for all the guys in our group. But I don't see her as a sister. At all. She's...