It seems to fall into the same class as obscenity: “I don't know what it is, but I know it when I see it.” Pinning it down (ooh, there’s something kinky… maybe) is impossible, because
the specifics differ from person to person.
What I will say, though, is this:
If you do it, it’s kinky.
If they do it, it’s perverted.
(And if you don’t do it but you’re still oddly intrigued, then it’s edge play. Because you’ll probably try it someday.)
Updated on March 16, 2011