You are the only single person at a dinner with two couples. You are the fifth wheel. The phrase comes from a wagon wheel, which has four wheels. A fifth is unnecessary. In social situations, a fifth wheel is an extra person who does not fit the group dynamic. They feel left out. The couples pair off. The fifth wheel checks their phone.

The term is usually used about dating. Two couples and one friend. The friend is the fifth wheel. It can also apply to any group where someone is superfluous. A third wheel is similar but for one couple. A fifth wheel is for two couples. The math is simple. The feeling is awkward.

Related terms

• Third wheel: an extra person with one couple.
• Seventh wheel: an extra person with three couples, rare but used for humor.
• Plus one: a guest invited to accompany someone.
• Gooseberry: British slang for a third wheel.

Being a fifth wheel is not permanent. You can leave. You can find your own partner. You can suggest a group activity that does not revolve around couples. The phrase is a joke, but the feeling is real. Nobody wants to be the extra wheel. The trick is to find a different wagon.