"Fries," they reply. There's no punchline joke there, but it's a tiny attempt to lighten the mood, if only for a moment. "Best just all salty, or dipped in milkshakes."

And they notice both the words and that undertone, though they find it easier to focus on the words. "...bet they do." Which is what they were worried about most in the first place. They want to get home, sure, very much, but there doesn't seem to be a way to have that happen, no matter what they do around the castle. At least in the Underground, they always had some kind of goal. Now they're just...feeling helpless and tense.

Not that it's enough to get them to waste their meal. For a while, there's just the noise of them chewing, which is probably sort of gross. They wipe the mustard on their pants, since the chair seems nice and they already spilled tea on it before, it doesn't need any more weird stains, and they wriggle around until they can drape their arm over the side.

Frisk can't see him, but they feel around until their fingers meet cranium, and they start to stroke.

"Sans..." This is not the best time to ask, at all, but they do. They don't entirely expect an answer anyway. "What's wrong?"