“Which? That you wouldn’t do anything devastating, or that I’m sappy? I’m not wrong about those.” She’s provoking him just as hard as she can, wanting to know where that glint is going to lead.
Nowhere, probably.
“You’re sappy. Simple enough,” he says with a bit of a look in his eye. The two are practically teasing each other at this point, attempting to provoke each other over the edge. Stiles doesn’t have anything in mind, but he can see something in her that shows that she has a plan.
It’s actually a bit intriguing.
“No I’m no~ot,” she sing-songs at him. “Prove it. How am I sappy? You’re a dork, I’m not sappy.” She leans over into his face again, eyes flashing and laughing. “Come on, Stiles, prove it.”