Lady Gaga is wearing just her undies to promote her new campaign "A Body Revolution."

The "Born This Way" singer posted the above photos on her Little Monsters website and revealed that she's been struggling with "bulimia and anorexia since I was 15."

Gaga said she started the campaign "to inspire bravery and breed some motherf**king compassion."

As Madonna would say ... "Strike a pose (in your yellow underwear), there's nothing to it..."

Robsten fans rejoice!

Robert Pattinson has moved back in with Kristen Stewart following a brief separation after it was revealed she cheated on him with her Snow White and the Huntsman director Rupert Sanders.

"They are living together and have reconciled," a source dished to Us Weekly.

Reports surfaced last week that the Twilight lovers "had a dramatic makeup," but the British hunk has not completely forgotten the On the Road actress' infidelity, as the source adds that he "is extra sensitive right now. He's insecure."

Although the couple previously shared a house in Los Feliz, KStew just purchased a $5 million Malibu beach pad, so we wonder where they will rebuild their love nest?

Let's hope RPatz realizes once a cheater, always a cheater!

Hot hookup alert!

Chris Brown and Nicole Scherzinger got a little kissy-kissy last night at Supperclub as surprised fans looked on ...

A source inside the club tells X17online.com exclusively:

"They were dancing close for a while and being all touchy-feely and finally Chris leaned into her. She put her head on his shoulder and they started kissing! I couldn't believe Chris was being so obvious about it!"

Chris Brown has been dating model Karrueche Tran since late 2011. Last week, however, Tran Tweeted "the end." The couple were rumored to have split in July but X17 photographer the two together as recently as Sept 16.

Nicole split with her longtime love Formula One racer Lewis Hamilton late last year but has been seen with him multiple times since. She's been linked to her Dancing With the Stars partner Derek Hough, her former X Factor US co-host Steve Jones, rapper Drake and others.

We have a feeling Rihanna might wanna get herself back to LA asap ...

Not only did Natalie Portman show off her new blonde 'do on Tuesday in Los Angeles, but she gave us a peek at her adorable son Aleph when she took him to a local park.

The Oscar winner had a blast pushing her 15-month old on the swings, and she held on tight as he tiptoed across a pole on the ground. If he hasn't started walking already, he's due to any day now -- she'll definitely have her hands full!

And speaking of being busy, her new hair color is for an upcoming role, but she hasn't yet revealed any details on the film. Our best guess is that it's for Jane Got A Gun, which she'll star in opposite Michael Fassbender.

Jenni "JWoww" Farley is officially off the market ... now that beau Roger Matthews has put a ring on it!

The Jersey Shore star confirmed her engagement to In Touch.

JWoww, who says Roger proposed while the couple were skydiving, tells the mag:

"I look over and see a hand-written sign: 'Jenni, will you ... ' and then I turned to him and freaked out. The whole time I'm screaming, 'What are you doing? What's going on? He's like, 'I want to spend the rest of my life with you! Will you allow me to?'"

Talk about taking their love to new heights! As for her engagement ring, JWoww adds:

"It's more than I ever expected. Roger's not an average-looking guy, he's huge: his personality, his size [6'4"]. So I always said, 'I want my ring like you — big! The bigger the better!'"

Perhaps she and co-star Snooki will have a double wedding on their reality show Snooki & JWoww.

A very pregnant Reese Witherspoon was spotted leaving the Beverly Hills Hotel on Tuesday afternoon, and even though she's just weeks away from giving birth, she looked amazing!

The Oscar winner and hubby Jim Toth haven't confirmed the gender of their first child together (this will be her third -- she has daughter Ava and son Deacon from her marriage to Ryan Phillippe), but Showbiz Spy reports that the couple are expecting a boy! A source tells the site, "They’re both really happy to be having a son, but especially Jim as it’s his first. He’s over the moon about it."

The actress was rushed to hospital with pregnancy complications last month, but she was released and given a clean bill of health within a matter of hours.

C'mon, just show the whole thing already!

Christina Aguilera has released a second clip from her upcoming music video, "Your Body," and thankfully we get to see the complete masterpiece this week. “Wanted you to be the first to see,” Xtina tweeted on Tuesday night. “New clip for #YourBody video. Premieres on @VEVO in a few days!!! XoXtina.”

“Your Body” is the first single off of her upcoming Lotus album, which will be released on November 13.

Kim Kardashian attended a Midori bash at Fred Segal in Santa Monica on Tuesday evening, and it sounds like she flew out from Miami just for this appearance! Earlier in the day Kim tweeted, "Back in LA for a few hours! Feels good to be home, even for this short time!"

Kim wore a low-cut velvet dress (we love the fact that she's color coordinating with the cocktail!) and she even slurped down one of the signature neon green drinks when she posed for photos. Kim has been a spokesmodel for Midori Melon Liqueur since 2011, and earlier this summer she hosted a party at Delano Beach Club in Miami with beau Kanye West by her side.

Before hitting the white carpet, Kim had a bit of a wardrobe malfunction when her dress popped open, but mama Kris came to the rescue and zipped her back up: