Britney Spears' Ex, Jason Alexander, Warns: 'It Won't Last'

Other partygoers oohed and aahed over Britney Spears' new Neil Lane engagement ring. But the pop superstar's attention was fixed on her fiancé, Jason Trawick, as they celebrated the talent agent's 40th birthday at Las Vegas' Sugar Factory American Brasserie on Dec. 16, a day after he popped the question. "Such an amazing time with my fiance," she later Tweeted. 

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Britney may find herself caught in a nightmare, however, if she becomes Trawick's bride, warns her ex Jason Alexander. "The relationship is a complete sham. He will end up hurting her," he tells Star. "If they actually get married, it will probably only last for a year or two, but not much longer than that."

Alexander, whose January 2004 quickie marriage to Britney was annulled after 55 hours, is speaking out, he says, before it's too late. "I think Britney is really unhappy but doesn't know how to get out," he claims. "I don't think she loves Trawick."

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FOR MORE ON HOW JASON ALEXANDER THINKS BRITNEY IS MAKING A MISTAKE, PICK UP THE NEW ISSUE OF STAR MAGAZINE — IN STORES NOW!