FAFO, phr. — Green’s Dictionary of Slang

FAFO phr.

[Urban Dict. suggests biker gang sl., Sheidlower F-Word (4 edn) attrib. to ‘African-American’]

(orig. US) a warning not to act in a way that impnges negatively on others, because it will bring retribution.

[2002		E. Jansen NetLingo 447: FOFO ‘F*# Off and Find Out’] [Sheidlower4].
[2007		S. Taylor Finding Platinum 35: Let me fuck around and find out what bitch stole my shit] [Sheidlower4].
2012		Twitter 28 Jan. 🌐 Fuck around and find out #FAFO [Sheidlower4].
2017		urbandictionary.com 15 Jan. Are those guys dangerous? FAFO.