When one of your partially romantic affiliations decides to stay over and you don't know whether it would be more or less awkward to offer them the guest room.
K: We should probably go to bed now
M: (internal narrator: do i offer him the guest room? this SUCH a guest room moment!) My bed's this way...
(retelling the story to a friend later)
N: How was having K stay over?
M: Mate i should've known there would be a guest room moment.