"Sophocles..." She doesn't know how to really say what she wants, her fingers twisted into the back of her hair as she struggles, "...I never want to tread on what you have with your cousin. You're closer than I ever could be, and I don't want you to feel like I'm replacing you. Please...if you think I'm hanging around too much, or taking up too much of his time, just tell me and I'll back off a little. You're...you're important to me too, and deserve to be respected."
Some part of him wants to be angry with her, and it's suspicious that she's just saying all of this to lull him into a false sense of security, that's she's fussing just to make herself look better or to garner sympathy of some sort.
But logically, he knows that's just silly, the thoughts a result of an overactive, insecure, anxious mind.
So he's quiet at first, simply letting her talk without interruption, and when it comes time to give her a response--he can't.
He isn't quite sure why, but it feels as though his throat is too tight to speak properly, and he rubs at his eyes with the back of his hands in what he already knows to be a vain attempt at dismissing tears before moving out of the chair he had been seated in.
"S-sorry, I--I can't--You..."
His breath catches in his throat and he shakes his head, moving to hide once again ('Stupid little coward', he hears something in his head tell him) in the storage closet that held various failed machines of his own making.
He slams the door behind himself, aware that there's still no light in the room, finding that even the terror brought on by total darkness was preferable to facing Mina right then.