Spears and K-Fed, as he was dubbed, started dating months after she annulled a quickie Las Vegas wedding to childhood friend Jason Alexander and before Federline's ex-girlfriend Shar Jackson gave birth to his second child. Email Britney Spears and Kevin Federline made a four-hour sex tape early in their marriage that he is now threatening to sell unless she gives in to his demands in their divorce case, according to a British tabloid, The News of the World. Spears, 24, hardly seemed despondent on that day, showing off a newly slim figure and chic blonde bob during a surprise appearance on Late Night with David Letterman in New York City. Something tells us the last chapter will be the one worth reading. Spears talked in often icky detail about her sex life to reporters and was frequently photographed barefoot in public. The pairing of the midriff-baring star and white-undershirt-and-stubble-clad dancer began in with all the hallmarks of a relationship meant to last just until Federline's first album release party. The tabloid says Spears fears release of the tape would short-circuit the comeback she's attempting to stage. Whatever may be in that tape, it really doesn't matter anymore. At Spears and Federline's September wedding, the groom gave his attendants white tracksuits with the word "Pimp" written on the back, and revelers dined on chicken wings. She's on her way back up. Spears sued after Us refused to issue a retraction. The lawsuit stemmed from an article published Oct. New parents have a new worry: Federline seemed to spend more time on apparently unproductive pursuits, like hanging out in Las Vegas, serving as the celebrity advocate for the preservation of the penny and challenging the occasional rival to a nightclub dance-off. The couple signed a pre-nuptial agreement thanks, Mama Spears!