third wheel
US /ˈθɜrd ˌwil/
UK /ˈθɜrd ˌwil/

1.
orang ketiga, pihak ketiga
a person who is in a situation with two other people who are romantically involved or who are very close friends, making the third person feel awkward or unwanted
:
•
I felt like a third wheel on their date.
Saya rasa seperti orang ketiga dalam temu janji mereka.
•
They're always together, so I often feel like a third wheel when I'm with them.
Mereka sentiasa bersama, jadi saya sering rasa seperti orang ketiga apabila saya bersama mereka.