POP mum Britney Spears was reportedly ducking for cover after an alleged x-rated home video with hubby Kevin Federline has surfaced. The Sun online reports a member of Spears' posse allegedly recorded the video nasty while Britney was pregnant with the couple's son, Sean Preston. He is reportedly threatening to release it. A source told US Weekly magazine: "He has threatened to release raunchy footage of the two taken before Spears looked pregnant." It is believed the tape was copied from the singer's alleged private collection with Federline. It wouldn't be the first time a celebrity has been caught out...