THE NEW FRESH KELLY OSBORNE!

She's finally got the body she has worked so hard to achieve, so it's no wonder Kelly Osbourne is keen to show it off.

The 25-year-old star wore a tight silver backless dress, fishnets tights and a red sparkly hat as she left Los Angeles' Viper Room after performing with the Pussycat Dolls last night.

Kelly, who lost three stone after appearing on Dancing With The Stars, took to the stage alongside the burlesque troupe, actress Carmen Electra and singer Mya in the invite-only show.

Shining in silver: Kelly Osbourne wore a tight sparkly backless dress as she left the Viper Room following her performance with the Pussycat Dolls last night

Earlier, Kelly had arrived at the venue wearing a sexy outfit of a sparkly bra, black PVC corset, fishnets, tiny hotpants and silver shoes.

Before her performance, Kelly told her fans which songs she would be singing, writing in her Closer magazine column: 'It’s going to be me, Carmen Electra, Mya and some of the other Dolls singing and dancing.

'I’m doing a song called 13 Men as well as Big Spender.

'It’s the first time I’ve really danced since filming Dancing with the Stars, but it’s so different.

'This isn’t stiff ballroom - it’s slinky and sexy!'

Sexy sailor: Kelly looked beautiful as she performed with a group of male dancers dressed as sailors

Slim and svelte: Kelly's nautical corset showed off her newly-slim figure and tiny waist

Kelly also posted a picture of herself wearing just a bra and knickers, with a cigarette placed seductively between her lips, on Twitter ahead of the show.

Pussycat Dolls founder Robin Antin also kept fans informed about the performance, posting a picture of Kelly in her full outfit from the dress rehearsal.

The picture was accompanied by the caption: 'Another sneak peek of HOT KELLY O! She's "Sweet Charity" re-invented!'

Giving it all she's got: The performance was also a return to singing for Kelly, who performed Big Spender and 13 Men

Loving it: Kelly had a smile on her face for the majority of the night and appeared to thoroughly enjoy her performance

It seems Robin isn't the only celebrity fan of Kelly's, judging by Kim Kardashian's posts on Twitter last night.

Kim, who was one of the selected few invited to watch the show, tweeted: 'Wow Carmen Electra is so beautiful!

'Watching her perform w the PussyCat Dolls....Kelly Osbourne is up next! Sexy show!'

She then added later: 'OMG @MissKellyO just killed it!!! She sang and danced and looks amazing!!!!! Love these costumes!'

Sparkles and fishnets: Kelly poses with co-stars Mya (centre) and Carmen Electra before the show

Ready to go: Kelly wore a black sparkly outfit, complete with black PVC corset as she arrived at the event with Pussycat Dolls founder Robin Antin

Desperate Housewives star Eva Longoria and Kelly's mother Sharon also attended to show their support for Kelly.

The Pussycat Dolls was started as a burlesque dance troupe by Robin in 1995, before they signed a record deal in 2003 and became the musical group they are today.

However, they still perform in venues around the world as a dance troupe, and have welcomed celebrity guests to join them on stage including Scarlett Johansson, Britney Spears, Gwen Stefani and Charlize Theron.

Stage regular: Carmen and Mya arrive for the performance with another Pussycat Doll

On top form: Carmen looked stunning in her sexy stage outfit of a striped bra, knickers and a sparkly corset

Meanwhile, Kelly, who showed off her amazing size six figure in a black Tony Ward dress at the Emmys last week, said daily cardio exercise is the key to her staying slim.

She told People.com: 'Ever since Dancing with the Stars, I’ve tried to get in at least a half hour of cardio a day - nothing too crazy.

'My trainer Sarah Hagaman is amazing! She knows how to motivate me to go that extra bit without frustrating me.'

Famous fan: Kim Kardashian and Kelly's mother Sharon turned up to support Kelly in her exclusive performance at the Viper Room

Lady in red: Eva Longoria also popped in to the venue to catch a glimpse of Kelly on stage

Kelly said recently that going on the U.S. TV talent show Dancing With The Stars was the best decision she ever made.

She said: 'I've completely changed the way I eat since doing Dancing With The Stars.

'A trick I've learned is to eat just a little bit of something that has no carbs and no sugar in it before you go to sleep because it keeps your metabolism going.

'They say you should never eat before you go to bed, but I've found just having a tiny little snack - like half an apple or something like that - before you go to sleep really helps.'

Hello, Twitter followers! Kelly Osbourne posed in just a sparkly bra as she prepared to join the Pussycat Dolls dance troupe on stage in LA last night

Sexy: The 25-year-old sang, danced and performed with the troupe last night