If it made Sans feel any better, Mettaton was far too self-absorbed in his own personal, body-horror tragedy to focus on Sans'. Besides, some small, blackout-drunk part of him feels like they've had that conversation before and, spoiler alert, it ended with Sans turning into a spooky dial-up modem.

Best not to bring it up for now.

Besides-besides, he's still offended. This was important and Sans is brushing it off like it was just another innocent prank! There's another hint of pink from under the bed, like the core is trying desperately to glare another hole into the skeleton. "well, wonderful. i'll remember that the next time he's curious about you."

...okay, so maybe he would focus on that.