Meaning "Elite", which on the internet is spelled "31337". This was then shortened to "1337" or "l33t" and pronounced "Leet". A l33t is one who "pwns" (owns) "n00bs" (players who are bad at a particular game) all day long locked away in their dark room, perhaps hacking a mainframe or two. Closely associated with h4x0rz (hackers) that are good at what they do.
I am teh uber l33t h4x0r that will pwn all teh n00bs! w00t!
Nobody denies that she's sexually active; not even Britney Spears herself. Sluts are women who have sex with numbers of men without having relationships with them. Britney Spears is married. Just because she's extremely attractive and is comfortable with expressing her sexuality rather than hiding it from the media doesn't mean she's a slut.
Britney Spears is pretty damn hot and nobody can deny that.