Well that's...a very telling sort of answer. Though not really in the way Sans had expected. He takes a step back, visibly startled, at Mettaton's reaction. But even if he can only guess at why the robot is reacting so badly, the fact of the matter is that he's upset this Mettaton again by asking what he thought might be an innocent question. Damn it.

"hey, hey..." Sans tries to make his voice soothing. It's hard to catch Mettaton's eye with the height difference between them. He tries to see about levitating himself up a bit, but...can't quite focus enough. So he reaches out to try and grab the robot's hand instead. "that's good. locked up is good. i only just got back, y'know? kind of not up to speed on anything."