Definitions by -KILLALL-

FATF 

An acronym meaning Flipping Across the floor. Used to express extreme laughter while chatting. Only to be used in situations that are actually too funny for a basic lol or rofl.

Other Uses:
Fatf-copter
Fatf-jet

Person #1 Today i fell down in front of the entire school and my pants ripped, i was so embarrassed. =[

Person #2 Fatf !!

FATF by -KILLALL- December 2, 2009