Inspired by the conversation in the Doctor Who Episode: Let's Kill Hitler. You know the one I'm talking about.
"I will never understand," Derek said. "Why you are making such an ordeal about some boy."
"Well, of course you don't," Erica replied with a roll of her eyes. "You're not normal. Besides, you've got Stiles."
"What? How've I got Stiles."
"Yeah, no. He doesn't have me."
"He's not mine."
"I'm not his."
"Oh come on," Erica said in complete disbelief.
"Yeah, it's got to be you two," Isaac added.
"Nice thought. Completely impossible."
"Impossible," Stiles agreed. "Not that, you know, I wouldn't love to. He's great, when he's not trying to tear my head off-"
"Yeah, he's the only one of you that's got a fully functioning brain on their shoulders but he's just-"
"He's straight," Stiles said, as Derek said "A friend."
"Penny in the air," Erica said with a smile, but Stiles and Derek didn't hear her over the intense staring that was going on between them.
And then, just like that, Stiles ran from the room. Derek stared at the spot where he'd just been standing, confused for a moment before realization set it. He disappeared after him.
Isaac grinned. "And the penny drops."