#undertext

If you tell Sans that Papyrus is uncool he tells you that sarcasm isn't funny (it's also v interesting to me that Sans never says an untruth if he can help it but hides a bunch, while Papyrus is occasionally dishonest, but usually for benign reasons). I've seen theories that Sans is also autistic and having difficulty reading tone (which is oftentimes the bulk of sarcasm) is a big one. Which is also neat to me is that Sans is really good at reading expressions. So in short, Sans typically only says something dishonest if it's blatantly part of a joke with an incoming punchline, right? And he doesn't like sarcasm, never uses it.

Papyrus will get sarcastic and cutting regularly when talking with Undyne when you call them both. The few times she misinterprets these it tends to be in the direction of "continuing a bit Papyrus might not have realized he started", not outright confusion. There's few if any times she legitimately fails to understand when Papyrus is being sarcastic, in a way that makes her feel bad; they're almost always in agreement or doing a bit.

What makes this really interesting to me is that while Papyrus tends to act kind of overblown with Sans - even moreso than usual, probably because he knows Sans won't be bothered with it or will go along - he never seems to use dishonesty or sarcasm when conversing with his brother.

Papyrus also has a lot of negative things to say about Hotland, but he only says "Glad I don't live in Hotland!" before you befriend Undyne. When he complains after that, it's always about specific aspects, usually of puzzles, a thing Undyne doesn't like much so they can have an agreement or fairly constructive conversation about it.

He also changes his opinion on Grillby's to agree with Undyne, but is fine making jabs at her love of anime, so he's not being like... obsequious at all times.

Alethi women writing undertext to everything