You know what?
That's not a flag question, next CALLER.
The Big Bang Theory Season 9, Episode 15
Unknown CALLER.
It's got to be them.
The Big Bang Theory Season 12, Episode 23
...suggesting that he has
no personal relationship with the CALLER.
The Big Bang Theory Season 2, Episode 15
It's time for a very special guest CALLER.
The Big Bang Theory Season 8, Episode 20
All right, we have our next CALLER.
The Big Bang Theory Season 10, Episode 21