Short for suck a fart out of my ass! Used in retort to a verbal absurdity or attack.

When you eat dirt for the first time and leave your family to build a shack in the woods

When things are going badly, or from bad to worse, you may be considered to be "sucking farts" or "sucking a fart";
generally have a shit time of it;

Term used briefly in Irish youth culture (between November 2005-March 2006) Used to express similar sentiment to common phrase "Kiss my Ass" while avoiding the cliche of what was a tired expression.
Rarely expressed now in any civilized culture.