I believe the back-scratching metaphor
describes a quid PRO quo situation...
The Big Bang Theory Season 2, Episode 16
Pro tip: if you find
strong women sexy,
The Big Bang Theory Season 12, Episode 19
- And finally, area rugs, PRO or con?
- Pro?
The Big Bang Theory Season 2, Episode 19
lt behooves you to be a PRO,
that's all. That's the fiction.
So chop-chop.
Breaking Bad Season 4, Episode 4
- And finally, area rugs, PRO or con?
- Pro?
The Big Bang Theory Season 2, Episode 19