"Sounds like everyone's been keeping up the weird factor while I was on vacation." It's a weak joke, but sincere in its own way. On a ship of so many, having a small crew within the crew is comforting. Not that Sans particularly enjoys leaving despair in his wake, but knowing his room-family cares about him is...

Well, it's something.

"Thanks. Uh, for the threat." That's sincere too, oddly enough. "Believe me, it'll help, you scare the shit out of me."