Britney shows off her bikini bod and more fashion news!

Welcome to the weekly fashion round-up, where we bring you the latest on supermodels, style, designers and everything in-between!

Which curvy star is lamenting the size of her assets? Which popstar's perfume is outselling those of her rivals?

Here's the lowdown on the latest fashion news!

Britney Spears shows off slimmed down bikini body, says she's no Kim Kardashian

Britney Spears has posted a new photograph of herself on Twitter, wearing a tiny green bikini.

In the photograph, the slimmed down 30-year-old singer, gave her 20 million Twitter followers a glimpse of her sunny California home that's decked out with an indoor aquarium.

"Having some fun in the sun. Don't want summer to be over!" the New York Post quoted her as writing as caption.

Britney has also revealed that she is no Kim Kardashian to be makeup-and-hair-ready every time she goes out.

The pop queen admitted that she prefers sloppy over style.

"I love my jeans and my sweats," the New York Post quoted her as telling Elle.

"I'm really just a tomboy at heart. So it's really hard for me to be like Kim Kardashian and be makeup-and-hair-ready every time I go out."

"On the other hand, when you do wear those sweats, you're like, 'Oh God, I should step it up a notch'," she added.

Jessica Biel, who is regularly praised for her style and beauty choices, appreciates the flattering remarks, but doesn't pride herself on the way she outwardly appears.

"It's a lovely compliment, absolutely," Stuff.co.nz quoted her as telling OK! Magazine.

"Beauty -- I think is so backwards. It's so about physical and it's just really not about that."

"I would never say: 'Oh no, not me, I'm not vain.' Because I think we live in a society where beauty is a really strange thing in this western world and the competition is just naturally there," she said.

The 30-year-old beauty has revealed that she always feels strain to stay in shape.

"I think there's pressure for me in my life as a human being simply because that is how I've always existed and because I like it," she added.

Lady Gaga's perfume 'Fame,' which features fragrance notes of blood and semen, has become the number one best-selling women's fragrance just a week after it hit the shelves.

Advanced fragrance technology means that the dramatic-looking black liquid turns clear as soon as it is sprayed in the air, and the bottle is pure Gaga -- black and gold featuring gilded monster claws.

This unique perfume concept has translated into cash registers ringing for Team Gaga; the 23.99-pound perfume has already sold more than both Beyonce and Madonna's fragrances did in their first week of launch.

"Lady Gaga is a true original and she has brought something completely new to the fragrance market," the Daily Mail quoted Superdrug beauty director Sara Wolverson, as saying.

"While initial reports promised slightly scary fragrance notes, the actual perfume is sophisticated, floral, addictive, moreish and sexy, which paired with the black liquid and dramatic styling is truly original."

"We knew Lady Gaga would be popular but have been astounded by the rush to be the first to buy the fragrance," she said.

In her perfume campaign, the 26-year-old singer is seen reclining with an arm behind her head, while holding the perfume in her other hand.

Scantily clad men -- who have been shrunk to miniature size -- are strategically placed over her body to cover her modesty.

"She is an artist that is never satisfied with the status quo - she always has this way of challenging everybody and trying to do something more, something different," Renato Semerari, president of Coty Beauty, said.

In more Gaga news, Vogue Magazine has gone a little too far with its retouching skills, after completely airbrushing its latest issue with her on its cover.

The magazine's behind-the-scenes montage of Gaga's September photoshoot shows the singer's bright purple Marc Jacobs gown bulkier and unflattering, the New York Post reported.

Her hair looks nothing like the styled mane on the cover but instead a bleached, frizzy nest.

And finally, her face is strong-featured and expressive in the picture, instead of the stoic nonchalance seen in the montage.

Jessica Simpson, who is struggling to shed the extra kilos she gained during pregnancy, has bemoaned the fact that her "boobs are too big to run."

According to USA Today, the 32-year-old said that she is doing about 60 minutes of cardio exercise a day in a bid to lose weight before the next season of Fashion Star.

"My boobs are way too big to run at this point. I'm just walking," News.com.au quoted her as saying.

Simpson, who gave birth to her first child on May 1, said that she is monitoring her food intake in an attempt to shed the extra kilos.

The singer has donned a pedometer to track her steps and is walking about 14,000 steps a day. She has also given up macaroni and cheese, which she says she indulged in while she was pregnant.

However, the one thing she is not depriving herself of is M&Ms (chocolate candy).

Katie Holmes has reportedly signed a deal to become the first ever face for an American beauty firm.

According to WWD the actress, who favours a bare-faced, almost no-makeup look, is a perfect fit for Bobbi Brown Cosmetics, which also shares a natural aesthetic, the Daily Mail reported.

The news remains to be confirmed by representatives for Bobbi Brown and the former Dawson's Creek star; however it comes as she prepares to stage the first-ever catwalk show for her label, Holmes and Yang.

Holmes, who founded the line with stylist Jeanne Yang, will join the likes of Diane Von Furstenberg and Donna Karan at the Mercedes-Benz Fashion Week at Lincoln Center on Sunday.

Freida Pinto went for a more daring dress than usual, as she attended the Jaeger-LeCoultre gala dinner celebrating the Rendez-Vous collection at the Giustinian Palace in Venice, Italy.

The 27-year-old actress bared her toned torso in a sari-inspired black and gold gown, which featured cut-out detailing around the torso area, the Daily Mail reported.

The Immortals star let her bold dress do all of the talking, merely accessorising it with a watch from a Swiss high-end designer watchmaker.

Pinto's hair was swept back in a chic chignon, and she wore minimal makeup.

Pinto also took time out to pose on the red-carpet with actor Clive Owen, who is one of the faces of the watch brand.

Emma Watson has revealed that her male friends weren't quite nice about her getting all her lovely blonde Hermione Granger hair cut short two years ago.

"Of course, men like long hair. There's no two ways about it. The majority of the boys around me were like, 'Why did you do that? That's such an error'," the Mirror quoted her as telling Glamour.

"And I was like, 'Well, honestly, I don't really care what you think!'"

"I've never felt so confident as I did with short hair -- I felt really good in my own skin. If I had it my way, I would have just kept it short forever," she added.

Christina Aguilera has revealed that she is loving her figure more now than ever before, insisting the only problem she's ever had with her weight is being too skinny.

"Actually, the challenge I've always had is being too thin," the Daily Star quoted her as saying.

"So I love that now I have a booty, and obviously I love showing my cleavage," she added.