
That was not 15th-century SOAP.
The Big Bang Theory Season 2, Episode 2

...that the
SOAP was...
The Big Bang Theory Season 5, Episode 16

And this recurring thing on a SOAP.
The Big Bang Theory Season 2, Episode 19

Soap spots. Wash 'em again.
The Big Bang Theory Season 5, Episode 16

"Number of days without
Amy's hair on the SOAP."
The Big Bang Theory Season 10, Episode 5