
You have to help.
It's in the ROOMMATE agreement.
The Big Bang Theory Season 4, Episode 2

Well, fine we don't have to have
a Roommate Agreement meeting
The Big Bang Theory Season 9, Episode 21

Roommate Agreement?
The Big Bang Theory Season 5, Episode 18

and be my ROOMMATE.
Then,
The Big Bang Theory Season 12, Episode 4

And she's proving to be
a valuable ROOMMATE.
The Big Bang Theory Season 2, Episode 10