JJ is a no good, back-stabbing bitch. Who will cheat on his girlfriend with a 7th grader. He will then get roasted by everyone, and pretend like nothing happened because he is a pussy.
A young man who enjoys to be involved in a circle jerk off session preferably with elderly men and the best activity is usually try to see who can lactate the most while the others drink what ever comes out.
JJ is often the abbreviation of a conceded person. A JJ is usually fairly short and suffers from little man syndrome. Apart from that a JJ will often times spend all his day shit talking on fornite, thus his natural pussy repellant. Of course you don't want to argue with him because that conversation will look like it came out of the famous movie "White Chicks" and often times lead to him having the last word or he won't shut up.