"Is this the part where you say if I hurt her, you'll kill me?"
"Look, I know this is supposed to be done by a big brother or the father or something. But Lucy is practically another part of me. She's my sister and my best friend and everything I've ever wanted to be - she is an amazing girl. I don't know where I'd be without her. And I'm not going to tell you that I'll kill you, because we both know perfectly well that Lucy is capable of hexing you six ways from Sunday."
Molly took a deep breath and continued. "So, what I came here to say was that you better treat her right. Do all of the things a boyfriend is supposed to do. Keep making her happy, because I've never seen her this happy in a long time. I couldn't imagine life without her. So don't screw this up, because you'll have hell to pay if you do."
This is dreadfully tiny. Oh well. For the Ultimate Diversity Challenge.