WHY BRITNEY SPEARS DOESN'T WEAR UNDERWEAR

A longtime friend of Britney Spears is exasperated that the singer keeps exposing herself private parts in public :The underwear thing is ridiculous - and I've told her," Tuesday Knight, a jewelry designer who has been a friend of Britney's since 2003, tells In Touch. "I've said, 'You cannot walk into a store wearing just a shirt with your underwear off.' I've told her that no one will take her seriously when she does this."

Tuesday believes Britney's insecurity after her divorce from Kevin Federline led to her exposing her private parts. "I love Britney - adore her - but she brings a lot of it on herself," says Tuesday, 38. "I've heard Paris Hilton, Lindsay Lohan and Britney talk about how they shock Hollywood just for the fun of it. They were discussing how they could play a little joke on all of us."

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"Britney has always been a good mother," she says. "I want people to know that she's the better parent - not Kevin!" Tuesday adds, "Britney asked me, 'Doesn’t anybody get to see this part of me?' The answer is, no, they don't. People just read about her not wearing underwear."

Tuesday blames Kevin, 29, for Britney's transformation from international pop star to train wreck. "I knew Britney when she and Kevin first met," Tuesday says. "She remade her entire life so it was all about him. She didn't even want to sign a prenup. Since then, I've watched her spiral downward."

Now, her problem of flashing could get her in even more trouble with the law. “The rules on indecent exposure are the same for everybody,� says attorney Myles Alderman Jr. of New York’s Alderman & Alderman law firm, which does not represent Britney. “If you can see her exposing herself at eye level, then that would be sufficient evidence and could create a legal issue.�

Before that happens, Tuesday hopes that her friend will realize that she doesn’t have to humiliate herself to get attention. “Britney doesn’t need to do it and she knows it’s stupid,� says Tuesday. “But she says that she just doesn’t like to wear underwear.�