
I believe the back-scratching METAPHOR
describes a quid pro quo situation...
The Big Bang Theory Season 2, Episode 16

Not a METAPHOR,
not an analogy,
it's a...
Breaking Bad Season 2, Episode 10

Yeah, me, too. I was stuck for a METAPHOR.
The Big Bang Theory Season 9, Episode 12

- A sports METAPHOR?
- Yes, baseball.
The Big Bang Theory Season 2, Episode 7

Luckily for you,
that's where the METAPHOR ended.
The Big Bang Theory Season 1, Episode 15