
being the third wheel
in a RELATIONSHIP.
The Big Bang Theory Season 11, Episode 14

Oh. Yes, it is. There's a loophole
in the RELATIONSHIP agreement.
The Big Bang Theory Season 6, Episode 1

...a RELATIONSHIP agreement
called the U.S. Constitution.
The Big Bang Theory Season 8, Episode 3

I think
this could really help their RELATIONSHIP.
The Big Bang Theory Season 9, Episode 24

you will not start a complicated
on-again, off-again RELATIONSHIP
The Big Bang Theory Season 5, Episode 13