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Not only did Jennifer Lopez perform her hit single "Booty" at Fashion Rocks 2014 on Tuesday night at Barclays Center in New York City, but the 45-year-old mother of two showed off her incredible physique in a sexy Versace gown. The short and sparkly outfit she switched into when she took the stage was also Versace, and while the low-cut detailing on the front of the dress was the same, it showed even more skin -- especially in the back!

Before twerking up a storm Lopez addressed the crowd and said, "Tonight we're gonna give it to you ... Are you ready?" The show was hosted by Ryan Seacrest and Rita Ora, Nicki Minaj, Usher and Pitbull also performed.

In case you missed it, check out J. Lo's sexy performance below!

Where was her over the shoulder boulder holder?!

Miley Cyrus left her NYC hotel to head to a party last night, and the singer opted to go au natural with no makeup, wet hair, and no bra! The "We Can't Stop" songstress was wearing a cream colored striped top, so she probably should have put on some undergarments! Then again, she went topless in only pasties the other night, so modesty isn't exactly her thing.

The twerking diva is in the Big Apple to debut her new art installation called Dirty Hippie during designer Jeremy Scott's fashion show tonight, but she has been making the rounds at all the fashion week parties during her stay.

Want to know what the pop princess is wearing for her art unveiling? This…

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Not everyone's a fan of the Biebs! Justin Bieber found himself among a throng of non Beleibers when he took to the stage with model Laura Stone during New York Fashion Week's Fashion Rocks event -- and got booed!

Apparently JB came onstage, fully dressed, and was met by a jeering crowd. Of course like any cocksure 20-year-old, who is internationally famous for both his singing and partying career -- he decided to attempt to silence the crowd by taking off his pants.

"I don't feel comfortable unless I'm in my Calvins. So, what's up? Is that cool?"

Then the constantly disrobing singer did what he does best -- and disrobed. We wonder how much Calvin Klein brand ambassador paid for that shout out? Probably a truck load of Calvins for life.

Along with an Instagram pic of the incident, the "Boyfriend" singer wrote, "Just stripped on national television hahahaha it wasn't planned lmao."

Taking off your pants on national TV? Just sounds like a Tuesday in Bieberland if you ask us!

Dunzo… for now!

Khloe Kardashian and boyfriend French Montana have decided to take a break in their relationship, Us Weekly reports.

"They are on a break. The relationship got too heavy and Khloe needed to take a step back," a source tells the mag. The reason? Apparently the rapper got to "needy" and the reality star couldn't handle it. "It grated on her that he became so dependent on her," the source added.

Adding to the tension was the fact that her family, particularly mom Kris Jenner and sister Kim Kardashian, didn't approve of the coupling. It sounds like French won't be keeping up with the Kardashians for the time being!

Maybe she's hungry?

Rachel Zoe stepped out for a New York Fashion Week event with husband Rodger Berman on Tuesday evening, and the stick-thin stylist couldn't be bothered to smile. Sure, she lights up when she's with her two adorable sons, but the rest of the time she definitely has her game face on! And she'd most definitely win a staring contest...

Last week it was revealed that Rodarte and Zoe would be collaborating for a branded T-shirt and sweatshirt collection, and while the apparel looks reasonably comfy, we can't imagine why anyone would want to pay $154 for the sweatshirt. Yes, it's really that expensive, and no, we're not the only ones commenting on the absurd price tags...

So round and juicy! Wait, are we talking about Khloe's butt or the contents of her grocery cart? Hmm...

On Tuesday afternoon Khloe Kardashian hit the gym, and after that she stopped by Williams-Sonoma and then the grocery store, where she stocked up on canned veggies and watermelon. Interesting combo...

While Khloe has been keeping a low profile on the west coast, on Tuesday her beau French Montana teamed up with Jennifer Lopez in New York City to shoot Fat Joe's new music video, "Stressin'." Earlier this year, J. Lo and French collaborated on her song "I Luh Ya Papi," so between J. Lo and Khloe, the rapper has been surrounded by a whole lotta famous booty. Wonder when he's coming back for his lady love?

Reese Witherspoon and husband Jim Toth landed in Los Angeles after spending the weekend in Canada for the Toronto International Film Festival, and we have to wonder if she matched her pink lipstick to his button down! I mean ... these two are known for their color coordination and super preppy threads!

Reese was at TIFF to promote Wild and The Good Lie, but it was her work in Wild that's already garnered her Oscar buzz, with critics calling it her big comeback. Sure, she captured our hearts in Legally Blonde and she won an Academy Award for Walk The Line, but she hasn't had a ton of amazing movies over the last few years. I mean, there's kind of a reason why we didn't watch This Is War...

But the funny thing is, Reese wasn't totally sold on the script from the beginning. In fact, the actress actually tried to back out of the big screen adaptation of Cheryl Strayed’s bestselling memoir. "I just had this total breakdown. You can’t make me do this movie,” Witherspoon told the audience at an event for the film at the Glenn Gould Studio on Sunday night. “I called my lawyer up and said, ‘I can’t make this movie. I’m going to have to be more raw, more emotional, more sexually explicit than I’ve been in any movie!’”

The film follows Strayed's 1,100-mile journey along the Pacific Crest Trail following her divorce and the death of her mother. We haven't read the book, but it's on our list -- and we should have plenty of time to finish it before Wild hits theaters this December.

Biker jackets and David Beckham? Sign us up!

The retired soccer superstar attended the launch party and signing for his new line of biker jackets with Beltstaff in New York City on Tuesday, and he worked it for photographers before stepping inside and greeting fans.

Of course, this was just two days after wife Victoria's big New York Fashion Week show, and he joked that he was in no way trying to steal her thunder. "Obviously she’s doing something far bigger than what I’m doing,” he told reporters. "Mine’s a capsule collection – and something that I’ve been obviously 100% involved in with every detail. But obviously with Victoria’s it’s a whole different monster. She’s done so well; over the years, what she’s created, and how she’s gained the respect of the fashion industry."

But he wouldn't be able to hawk a line of biker jackets unless he drove a motorcycle, right? Not only did he chat about the process behind customizing his 93 Harley-Davidson Knucklehead, but he also talked about the nasty spill he took last week, in which he injured his hand. “My first time," he said with a wince. "Not a great experience, but I was lucky. Riding bikes is dangerous at times, but so is walking down the street. It’s not a nice experience, but it happened. Luckily I only suffered a few bruises and cuts, and a dislocated thumb.”