Some context Cook'll never provide: He doesn't know what the fuck Sarah means by "normal." All he knows is that that's something he's never been, never really seen and, should he see it one day, something he thinks is more fucked up than whatever they (he and all his family, friends and acquaintances) could ever be. He knows what he was at seventeen and has seen what Sarah was at seventeen. There's a difference; he's not stupid enough to miss that. But he doesn't see what part "normal" plays on this conversation.

He turns away at the last phrase, tilts his head back and pours the last drops of his beer down his throat. "Why, when we've already got each other sussed out?" Calling it a rhetorical question is being generous. There's a careless finality to it, despite the phrasing. He's wrong and she's scared. Done.