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2.
stands for "You. made. a. funny." quoted by Stewie on the comedy,"Family Guy."
friend~ yeah, pure goosebumps!
you~ haha, ymaf!
by BeckBeck March 25, 2007
 
1.
Acronym for "you make a floppy sandwich" or "you make a floppy subway"

When someone makes a floppy sandwich/subway it severely decreases the quality of the experience at Subway.
NO. I WANT NICOLA TO SERVE ME, YMAFS!
by MikeyRyan2404 March 05, 2011