We are such dorks

Friend 1: So do you want to do something tomorrow night?
P & G: I'd like to, but I might be having a dinner party.
Friend 2: Might?
P & G: Well, we had definitely planned on having one sometime, but we could never find a time that worked, and then everyone went on vacation, so I sent an email that I would be eating dinner tomorrow at 7, and if anyone wanted to come they were welcome, but otherwise I'd have my book to keep me company.
Friend 1: It's like Schroedinger's Dinner Party!
Friend 2: You may or may not have dinner guests, but you won't know until you serve dinner!
P & G: ...I knew there was a reason we were friends.

N.B.- Some, but not all, of the guests attended tonight's dinner party. Does that mean the cat is terminally ill?