Third wheeling is the act of socializing with a couple, often as an unwanted, unnecessary third person. This can often be related to adding a third wheel on a garbage can: unnecessary for your trash.

someone who never really fits in with the other duo. They make everything awkward and don't ever let the couple make a move.

The person in a group of people (usually two, though sometimes more) who is most often left out of things.

The third wheel is usually there for one of two reasons - to act as a mediator, such as with a couple, or to be the "convenience friend" when nobody else is there to hang.

Third wheels are not normally forcefully excluded from activities, but they're not usually invited or informed about them either.

Not to be confused with being third-wheeled.

Usually the odd one out of the group (3 people), this person does not fit in and typically has a strong intolerance for eggs.

When kunha goes with his sister and her boyfriend to steal the girl.