
Being your girlfriend is so CHALLENGING.
The Big Bang Theory Season 8, Episode 24

It's like me CHALLENGING you
to a sexy pants contest.
The Big Bang Theory Season 8, Episode 19

I know what a CHALLENGING man he could be,
The Big Bang Theory Season 9, Episode 14

It really doesn't matter
as long as it's CHALLENGING.
The Big Bang Theory Season 10, Episode 22

"The CHALLENGING
climate of Scandinavia
The Big Bang Theory Season 12, Episode 23