Forever 13
Hot Topic. Used as a mildly derogatory term and a wake up call towards grown men and women who are stuck in the early adolescent frame of mind.
"Seriously Paul, you do realize you're 32. So why don't you just quit wasting your hard earned money in the Forever 13 and come with me to Marshalls?"
13 forever
It means MS13 forever as in gang terms.
"Ay gang 13 forever"