"The CHALLENGING
climate of Scandinavia
The Big Bang Theory Season 12, Episode 23
Intimacy in any form
has been CHALLENGING for me,
The Big Bang Theory Season 9, Episode 11
but the truth is,
Amy is just as CHALLENGING.
The Big Bang Theory Season 10, Episode 5
Not CHALLENGING?
I was humiliating the man.
The Big Bang Theory Season 6, Episode 6
It really doesn't matter
as long as it's CHALLENGING.
The Big Bang Theory Season 10, Episode 22