Where did this term come from? It mostly seems to apply to male genitals, but I've heard a song in which the female singer (Kesha?) makes reference to "boys trying to touch my junk". So unless she's a transexual or a hermaphrodite, the meaning may be getting broader. Anyway, where does this use of the word junk come from?
Maybe she means the "junk" in her "trunk". Either way it's better than the Donnie Baker favorite: "Pork Sword".
I first heard it in 2002 when George Lopez said he was like Jennifer Lopez "but without all the junk in the trunk."
I prefer the British colloquialism of referring to them as their "naughty bits", which gets abbreviated to just bits sometimes.