Her sentence clips, cuts short. They can't precisely tell why. Something she isn't saying, or something she doesn't want to say. They don't...press, because pressing would be rude, and they've learned that most people don't like to have their secrets pried up like old bits of floorboard.

Just another conversation that neither of them really should have when things are like this.

"Okay," says Frisk.

That's easy. They can shut up, and be good. They're good at that.

"But it's okay, if you wanna know later."