fer' serious

For serious;Serious; Seriously.
Ususaly as a question.

"Oh my gosh! Are you fer' serious?"
or
"Yeah guys. I'm fer' serious!"

Fer serious

To answer back to something that you can't believe

Boy-did you see that Britney Spears shaved her head?
Girl-Fer serious?

fer serious

an exclamation meaning "are you serious"

Holy crap, are you fer serious!?!