Serious Sarah

A person who takes things way too seriously and cannot take a joke.

Jane is such a serious Sarah!

serious-er

more intense than serious.

it was so much more serious-er when he pulled a gun.

mad serious

when something is so serious it makes you mad

Dude 1: bro did you cat really freeze outside

Dude 2: YES BRO IM MAD SERIOUS.

Frotally Tucking Serious

When someone is dead serious about something. Not a joking matter.

Get him to the Greek is one crazy ass movie. I am frotally tucking serious!

Dat serious

phrase used to validate an idea or person

we the coolest kids doing it like dat serious

Don't take it seriously

You definitely can't accuse me of THAT, that's for damn sure. I am like, super militant.

Hym "You can't say that I don't take it seriously that's for damn sure."

As Serious As Joe

A phrase used to express the lack of care or interest in the particular topic; usually used in school scenarios, when your teacher assigns you something, dont give a shit, but then finish with an A in the class.

Example 1:
Yeah I haven't done my homework for the past few days, but I still aced the test...
Wow you've been As Serious As Joe lately.
Example 2:
Hey did you read chapters 27 & 28?
No, Ill just read them next week, im taking this As Serious As Joe