Kitty: *reads* I dare Sans to tell Papyrus he's not cool.

Either that or he needs to tell Frisk that she's gonna be a big sister soon. *stops reading*

Sans: I'm going for second option, kiddo. Hey, Frisk.

Frisk: What?

Sans: You're gonna be a big sister, soon.

Frisk: ... I don't understand. What do you mean?