Grammy Awards 2013 Biggest Dress Code Violators: Jennifer Lopez, Kelly Rowland, Rihanna and More!

USMagazine, Monday, February 11, 2013, 10:00am (PST)

Fashion police was in full force at the the 2013 Grammy Awards. In advance of music's biggest night (and often most scandalous), CBS sent an e-mail to guests outlining a strict dress code, but some stars decided to ignore the rules.

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"Please be sure that buttocks and female breasts are adequately covered. Thong type costumes are problematic. Please avoid exposing bare flesh under curves of the buttocks and buttock crack. Bare sides or under curvature of the breasts is also problematic," the e-mail stated (via Deadline). "Please avoid sheer see-through clothing that could possibly expose female breast nipples. Please be sure the genital region is adequately covered so that there is no visible 'puffy' bare skin exposure."

Not all stars followed the new dress code, however, and still rocked high slits, low-cut tops and sheer dresses on the red carpet at the Staples Center in L.A. Sunday, Feb. 10.

Take a look at the top 10 biggest dress code violators below.

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1. Jennifer Lopez

As Pitbull joked on stage, Lopez "inspired the memo." The "Dance Again" singer, who wore the infamous green, cleavage-baring Versace dress to the 2000 Grammys, flashed a different body part this year: her leg. "They didn't say anything about leg!" Lopez, 43, who wore a black Anthony Zacarello gown with a super high slit over her right leg, told E! News. "I thought I was being such good girl -- [just] a little shoulder and a little leg."

2. Kelly Rowland

The former Destiny's Child member, in a risque Georges Chakra Couture dress with strategically placed cutouts on her cleavage and thighs, violated numerous rules, chief among them showing ample cleavage and underboob. "Ha! It's so funny. I thought about the dress code and thought about it again and that's about it," Rowland, 32, told reporters backstage. "I respect.  See, I wore clothes!"

3. Rihanna

The "Stay" singer, 24, decided to ignore the "please avoid sheer see-through clothing" part of the memo. Rihanna's nipples were visible in a sheer red Azzedine Alaia dress while posing on the red carpet. 

4. Katy Perry

Crazy cleavage! The "Wide Awake" singer, 28, styled a mint green Gucci dress that flaunted her impressive cleavage with a jewel-outlined cutout. "I was inspired by Priscilla Presley in the '70s . . . Married to Elvis Presley, of course." she told E! News. "The bigger the hair the closer to God."

5. Alicia Keys

The memo said "bare sides or under curvature of the breasts is also problematic," but the "Girl on Fire" singer didn't seem to have a problem exposing her underboob. While performing onstage with Adam Levine, Keys, 32, changed from her Alai red carpet dress into a sheer black design that revealed the "under curvature" of her breasts.

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6. Miranda Lambert

The country singer was not a fan of the new dress code, and decided to wear a low-cut Roberto Cavalli gown that showed off her decolletage. "That was weird. My stylist was reading it to me. I can't get over the puffy skin part," Lambert, 29, told Entertainment Tonight. "What is puffy skin? Don't show puffy skin. I don't want to see anyone's puffy skin."

7. Ashanti

The 32-year-old singer bared a lot of cleavage and some serious leg in a sexy Tony Ward Couture gown. Working with her stylist, Ashtanti told reporters, "We had 11 options, then I saw this. I was like, 'Oh, my gosh. She is beautiful." She added, "I just thought it was kind of vintage and romantic and still classy and sexy at the same time."

8. Kat Dennings

Nip slip risk! The Two Broke Girls star, 26, who presented an award during the show, flaunted major cleavage in a sexy, strapless Vivienne West dress.

9. Monyetta Shaw

Ne-Yo's longtime girlfriend showed off her curves in a daring, low-cut little black dress. "You might be looking too hot for the wardrobe rules," Nancy O'Dell told her on the carpet."No, I think we're good," Ne-Yo said.

10. Christine Teigen

John Legend's gorgeous fiance revealed her midriff and right leg in high-slit, Joy Ciocci dress. But the 27-year-old model argued that she's following all the rules. "Wearing Joy Cioci tonight!" she tweeted. "Tried to avoid all rules of genitalia, side boob and puffy parts."

This article originally appeared on Usmagazine.com: Grammy Awards 2013 Biggest Dress Code Violators: Jennifer Lopez, Kelly Rowland, Rihanna and More!