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

It's a sports METAPHOR.
The Big Bang Theory Season 2, Episode 7

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

...the terms of your METAPHOR
by acknowledging her existence. I'm out.
The Big Bang Theory Season 2, Episode 8

I believe this is an extension
of the death METAPHOR.
The Big Bang Theory Season 2, Episode 8