https://www.urbandictionary.com/define.php?term=FFS
Sep 10, 2002 · Acronym for, for fuck's sake. An acronym for "For fuck's sake", meaning "I can't believe this shit, I demand you to stop" The source is For Christ's sake ("in Christ's name please explain/stop that"). Swap in Fuck All ("nothing") for the deity, and you get an urban, angry, non-religious, expletive, demanding equivalent of "Oh My God, do something".