Teen Wolf Season 1 Episode 11

Allison: Nothing's wrong, I just have a lot on my mind.
Lydia: You could smile, at least. Ever hear the saying "Never frown: someone could be falling in love with your smile"? Smile, Allison. I'm buying you a dress.
Allison: I have to admit, as far as apologies go, that's more than I expected.
Lydia: Excellent.
Allison: But not as much as I'm going to ask.
Lydia: What? What's that supposed to mean?
Allison: It means you're going to cancel on whatever dumb, 'roided up jock you said yes to, and you're going to go with somebody else.
Lydia: Who?
Allison: [points out Stiles] Him. Oh, don't frown, Lydia. Someone could be falling in love with your smile!