Britney Spears sings 'I'm gonna mark my territory' in her new song 'Perfume' from her recently released album Britney Jean.  In the track's music video clip, Spears appears to be in Vegas with a guy who looks a lot like her ex-husband Kevin Federline, and she's green with envy over his escapades with a gal pal.  And she's gonna rant about it in nothing but her bra and undies.