When there are more people than there are rooms, someone's going to end up having to share a room. Sharing a room will usually lead to fighting, regardless of how well the two people get along normally. These fights will usually be over personal space, annoying habits, or lack of privacy.

Sometimes the people sharing the room are an Odd Couple, and do not get along well because of opposing personalities. Other times they are eager to share a room and end up hating it.

The two people sharing the room are usually Siblings who have to share a room full time. Two people have to temporarily share a room during a vacation. And in some rare cases, a romantic couple.