[Yeah, Sans probably shouldn't be squirming around purposelessly like that. And Papyrus could stand to be jumping into action, like picking his brother up to help get him to safety. But they're both in pain, surprise and distraction enough not to think these things through right away. This danger isn't coming with the dubiously convenient warning of a kid covered in dust to make the nature of the situation clear, after all.]

Wait, don't wear yourself out yet. [His attention's flickering between their respective states, and keeping an digital view on the mystery monster. Not approaching, but watching...?] M-Maybe it knew the address... That's on record. Or it might have been stalking... well, me, I don't check for people following me. [Some regrets, there, but it hasn't actually been a problem before.] So, somewhere we don't normally go...?

[What's a good place to avoid weird monsters, though?]