"Oh, for god's sake, Caleb, I know you're not an asshole." She glares at him, but she can see the flash of hurt in his eyes, and that only makes her sigh again. "Sometimes you can be clueless, but I know it's not...you don't do it deliberately. I really do know that, alright?"

What it is, really, is the fact she knows that the unintentional things can hurt the most. It's happened to her, it's happened to Neil, and likely even to Caleb. Maybe it'll always happen, no matter how often she tries to prevent it.