Is he SERIOUS?
The Big Bang Theory Season 2, Episode 23
Serious as the hepatitis
The Big Bang Theory Season 12, Episode 17
No, I'm SERIOUS.
The Big Bang Theory Season 11, Episode 11
Sounds SERIOUS. Have I been a bad boy?
The Big Bang Theory Season 10, Episode 23
You are not SERIOUS.
The Big Bang Theory Season 12, Episode 17