
They say it's the perfect METAPHOR
for my incandescent talent.
The Big Bang Theory Season 2, Episode 4

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

Wow, was that your first ever
sports METAPHOR?
The Big Bang Theory Season 12, Episode 10

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

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