Tuesday Knight: Why Britney Spears Wears No Underwear

Like the rest of us, a longtime friend of Britney Spears is exasperated that the singer keeps exposing herself in public.

"The underwear thing is ridiculous â€" and I've told her," Tuesday Knight, a jewelry designer who has been a friend of Britney's since 2003, tells the latest issue of In Touch Weekly.

"I've said, ‘You cannot walk into a store wearing just a shirt with your underwear off.' I've told her no one will take her seriously if she does."

Tuesday Knight believes Britney's insecurity after her divorce from Kevin Federline led to her exposing her providing us upskirt pics quite often.

"I love Britney â€" adore her â€" but she brings a lot of it on herself," says Tuesday, 38. "I've heard [fellow crotch shot queens] Paris Hilton and Lindsay Lohan talk about how they shock Hollywood just for fun."

"Britney has always been a good mother," she says. "I want people to know that she's the better parent, not Kevin!" Tuesday Knight 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 wearing no underwear."

Tuesday Knight blames Kevin Federline for Britney's devolution.

"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, Britney Spears' ongoing problem of wearing no pants and flashing her baby factory 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 Knight 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."