Something about that sets Sans back - the idea that his anxieties are so fully on display just seems completely distasteful, and a little bit frightening. He freezes for a few more moments, and then clenches his fist, taking a step back while watching the other skeleton warily.

On a deeper level than he can truly understand, he's knows he's not supposed to do that. He knows that it's more trouble than it's worth. His anger is temporarily weight down by the fact that he doesn't know whether he's more frustrated or ashamed.

Though to a stranger it sounds like idle boasting, Sans can't possibly know how right Papyrus is about that assumption.

"Nothing I'm waking up to is any better," he says, after a moment, pressing a hand over his left socket. His voice is softer, weakening down to something exhausted after that flareup of temper has passed. "I think they really did a number of me...an' there wasn't a lot there to start with."

He looks up and around the room again with a haunted expression.