If you think that the worst thing Britney Spears has ever done in her career was the head-shaving incident or the 2002 movie "Crossroads", you were totally wrong.
In a recent interview with The Telegraph, the singer admitted that her documentary mini-series "Chaotic," with then-husband Kevin Federline, was her biggest career blunder.
"I would never do something like that again," Spears told the publication.
