You haven't given me a gift,
you've given me an OBLIGATION.
The Big Bang Theory Season 2, Episode 11
...an inherent OBLIGATION
to maintain confidences?
The Big Bang Theory Season 2, Episode 1
I have a contractual OBLIGATION...
The Big Bang Theory Season 6, Episode 1
As teacher, it's your OBLIGATION
to separate your personal idiosyncrasies...
The Big Bang Theory Season 1, Episode 17
...but you two
don't feel any OBLIGATION to join in.
The Big Bang Theory Season 1, Episode 4