It's time for a very special guest CALLER.
The Big Bang Theory Season 8, Episode 20
Unknown CALLER.
It's got to be them.
The Big Bang Theory Season 12, Episode 23
Hello, CALLER. You are on with Penny and Wil
from Serial Ape-ist 2.
The Big Bang Theory Season 8, Episode 20
We have another CALLER.
Hi, you're on Fun with Flags.
The Big Bang Theory Season 9, Episode 15
You know what?
That's not a flag question, next CALLER.
The Big Bang Theory Season 9, Episode 15