This is a abbreviation and short for Justin Frink a fictional character who is native. Its stands for when someone gets there Facebook status change jokingly to something comical all in good nature and the someone gets all bitchy like a little girl and deletes you off there face book and puts a lock on there a computer and last but not least takes there hard drive off there Xbox so you cant play Gears of War all weekend
Bobby: "Dude I so just changed Jimmy's face book status too i love men"
Rick: "Dude i saw that shit it was funny and did you see Jimmy deleted you as a friend hahah"
Common acronym used as an insult towards guys. The true meaning of JF is top secret, but in general applies to any player, jackass, bonehead, jerk, or piece of crap boy that you have had unfortunate dealings with.
"So then I found out he said the exact same thing to two other girls."
"Ew, what a freaking JF."
Actual meaning: JF - stands for Jocelyn Flores, a hit song created by rapperXXXTENTACION. 8 stands for the eighth line in Jocelyn Flores: "I'm in pain, wanna put ten shots in my brain".
So being in JF-8 mood is basically being suicidal.