
It's a CONVERSATION starter.
The Big Bang Theory Season 3, Episode 11

...to provide Amy with CONVERSATION
and casual physical contact.
The Big Bang Theory Season 6, Episode 1

...to introduce
an alternate topic of CONVERSATION.
The Big Bang Theory Season 4, Episode 7

into a CONVERSATION for years.
The Big Bang Theory Season 12, Episode 3

...but tread carefully because it may be
the last CONVERSATION we ever have.
The Big Bang Theory Season 3, Episode 5