I'm SERIOUS,
JPL's actually developing a robot arm
The Big Bang Theory Season 10, Episode 7
(chuckling)
Oh, you can't be SERIOUS.
The Big Bang Theory Season 5, Episode 21
l am SERIOUS too.
Breaking Bad Season 4, Episode 2
How SERIOUS were you two?
The Big Bang Theory Season 7, Episode 19
Serious?
Breaking Bad Season 2, Episode 5