CGAF 

'Couldn't give a fuck'... For when you simply can't give a fuck

John: "Hey, did you hear? The X-Factor final is on tonight!"

Paul: "Oh really, well I CGAF John. I really CGAF in the slightest"

CGAF by PTruman December 13, 2009

CGAFF

I couldn't give a flying fuck
The ultimate state of just not caring.

A tamer, less aggressive version, IDGAF may be used in situations when more caaaaaaare has been expressed.

Person 1: hey man, have you finished that history report due Thursday?
Person 2: I CGAFF man..icgaff.

CGAFF by cgaff man February 3, 2012