What would Mary Berry say? Bake Off's Mel Giedroyc shows off her sexy side in lacy bra as she takes part in star-studded charity performance of The Rocky Horror Show

She's one of the UK's best-loved TV stars, and is currently on screens every week as one of the hosts of The Great British Bake Off.

But Mel Giedroyc showed off a different - and racier - side as she flashed her chest in just a lacy bra while on stage during a one-off gala charity performance of The Rocky Horror Show at London's Playhouse Theatre on Thursday evening.

The affable presenter, 47, looked just as shocked as her fans might as she unveiled her decidedly sexy look for the evening.

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She's not shy! Mel Giedroyc showed off a lesser-seen side of herself as she bared her chest in a lacy bra during a special charity one-off performance of The Rocky Horror Show on Thursday night

She's not shy! Mel Giedroyc showed off a lesser-seen side of herself as she bared her chest in a lacy bra during a special charity one-off performance of The Rocky Horror Show on Thursday night

Wearing a pair of high-waisted black trousers with a shiny blue cummerbund, her chest was scantily clad with a black and nude lacy bra.

The long-time comedy partner of Sue Perkins' on-stage attire was finished with a long black jacket with tails and a white collar with a tiny bow tie, adding to the effect of her nearly bare generous cleavage.

As well as the surprisingly risqué look, though - that would have surely raised the eyebrows of her Bake Off co-stars Mary Berry and Paul Hollywood, the comedian injected humour into the performance, looking incredibly animated as she did her thing in front of the audience.

Big moment: The Great British Bake Off star, 47, joined others at the star-studded performance of the iconic musical at London's Playhouse Theatre

Big moment: The Great British Bake Off star, 47, joined others at the star-studded performance of the iconic musical at London's Playhouse Theatre

Sexy scientist: Another scene saw Mel don a white coat, her generous chest still well and truly on display

Sexy scientist: Another scene saw Mel don a white coat, her generous chest still well and truly on display

She pulls it off! Mel - the famous comedy partner of Sue Perkins - looked at ease in her racy yet still conservative attire as she posed later on at the show's afterparty

She pulls it off! Mel - the famous comedy partner of Sue Perkins - looked at ease in her racy yet still conservative attire as she posed later on at the show's afterparty

Doing her bit: Mel and her co-stars were there to help raise money and awareness for Amnesty International, with the show being broadcast live in cinemas across the UK and Europe on Thursday

Doing her bit: Mel and her co-stars were there to help raise money and awareness for Amnesty International, with the show being broadcast live in cinemas across the UK and Europe on Thursday

Stunning stockings: Mel was joined by Ade Edmondson and Emma Bunton, as they each took on the role of The Narrator in Richard O'Brien's iconic musical

Stunning stockings: Mel was joined by Ade Edmondson and Emma Bunton, as they each took on the role of The Narrator in Richard O'Brien's iconic musical

A timeless classic: The audience was thrilled to see the show - which is over 40 years old - revived with a starry cast

A timeless classic: The audience was thrilled to see the show - which is over 40 years old - revived with a starry cast

Mel appeared alongside Stephen Fry, Ade Edmondson and Emma Bunton at the one-off charity performance of the iconic musical, created by Richard O'Brien, in order to raise money for Amnesty International.

Each of them took on the role of The Narrator in the groundbreaking revival of the show. 

Fans of the iconic and groundbreaking musical - which was turned into a hit movie, The Rocky Horror Picture Show, 40 years ago in 1975 - were able to watch Thursday night's performance as it was streamed live from the Playhouse Theatre to cinemas aross the UK and Europe.

And it's no surprise that Mel and her co-stars were clad in the sexiest of stage outfits, as the show has gone down in history as one of the most sensual and daring of all time, the story focusing on a transvestite scientist and a newlywed couple who accidently stumble upon his home and debauched lifetstyle.

A story to tell: Wearing a tiny pair of black hot pants teamed with a tuxedo-style blazer, the singer cut quite the raunchy figure for her role as one-fourth of the evening's narrators

Baby Spice no more! Emma, 39, wowed as she donned a racy pair of stockings with towering heels and a blazer as she hit the stage

Co-stars! Mel and Emma posted backstage together ahead of the performance during rehearsals

Co-stars! Mel and Emma posted backstage together ahead of the performance during rehearsals

Working it: The 39-year-old blonde beauty pulled out some serious moves as she well and truly got her teeth into the one-off role

Working it: The 39-year-old blonde beauty pulled out some serious moves as she well and truly got her teeth into the one-off role

Star-studded: Emma was one of the many famous faces taking part in the charity event, which was the highlight of 11 performances of The Rocky Horror Show

Star-studded: Emma was one of the many famous faces taking part in the charity event, which was the highlight of 11 performances of The Rocky Horror Show

Mel was among one of the four narrators on the night, with QI host and loveable Brit Stephen also taking on the role.

While his look was on the safer side for the evening - the 58-year-old donned a simple black tuxedo - comic Ade showed off his fun side, and impressive legs, in a pair of stockings and suspenders worn under his shirt and checked jacket.

The 58-year-old has a history with the musical, having appeared on the West End stage in 1990 as leading character Brad Majors.

Bow down: Stephen Fry was another of the stars acting as The Narrator during the performance

Bow down: Stephen Fry was another of the stars acting as The Narrator during the performance

A living legend: Ade, 58, didn't let Mel be the only one to work a risque look, as he donned a pair of stockings under his short and jacket

A living legend: Ade, 58, didn't let Mel be the only one to work a risque look, as he donned a pair of stockings under his short and jacket

What a curtsey! The comic showed off his impressive legs in the sheer stockings, which he teamed with heels

What a curtsey! The comic showed off his impressive legs in the sheer stockings, which he teamed with heels

He's back! The musical's creator, Richard O'Brien, was of course on hand to lend his talents to the performance

He's back! The musical's creator, Richard O'Brien, was of course on hand to lend his talents to the performance

Matching Mel in the sexy stakes was Emma, 39, who rocked a flattering black jacket and seriously alluring stockings of her own, as well as a pair of towering heels. 

And it wasn't just about the celebrity faces on the stage, as plenty of other stars attended the gala night.

Emma was supported by her best friend and Spice Girls co-star Mel C, who cut a seriously stylish figure in a black mesh crop top and a maroon leather pencil skirt.

Former Girls Aloud beauty Kimberley Walsh also added to the star-factor of the audience, the blonde beauty flaunting her slimline curves in a pewter coloured jumpsuit.

Chic Spice! Mel C was one of the famous faces in the audience, and she looked divine in a mesh-style black crop top and maroon leather pencil skirt

Chic Spice! Mel C was one of the famous faces in the audience, and she looked divine in a mesh-style black crop top and maroon leather pencil skirt

Flattering: The singer looked lovely in her chic eveningwear, as she went along to support her best pal and Spice Girl co-star Emma

Looking good: Kimberley Walsh also went along for the evening, covering her slender curves in a pewter jumpsuit with a cinched-in waist

Looking good: Kimberley Walsh also went along for the evening, covering her slender curves in a pewter jumpsuit with a cinched-in waist

Having the night off! The busy mum-of-one looked pleased to be having a night off from mummy duties as she entered the London theatre

Having the night off! The busy mum-of-one looked pleased to be having a night off from mummy duties as she entered the London theatre

Leggy: Emma looked incredible as she made her way out of the event's after party 

Leggy: Emma looked incredible as she made her way out of the event's after party 

Posing up a storm: The former Spice Girl happily posed with fans after her spectacular performance

Posing up a storm: The former Spice Girl happily posed with fans after her spectacular performance

Time for bed? Clearly exhausted from her busy night, Emma headed home with her doting husband

Time for bed? Clearly exhausted from her busy night, Emma headed home with her doting husband

The 33-year-old singer and TV personality looked a treat in her figure-flattering all-in-one, which she teamed with a pair of towering pale grey platform heels.

Thursday night's star-studded extravaganza was the highlight of a nine-night run of performances of The Rocky Horror Show at the Playhouse Theatre, each of which starred its creator O'Brien. 

Ahead of the big night, Akita Hancock - Amnesty International UK's Events Manager - said: 'We're delighted that so many special guest stars have agreed to be part of what promises to be a spectacular performance. 

'The Rocky Horror Show is a fabulous celebration of freedom and expression - a fundamental area of Amnesty's work. So this is a perfect opportunity to rally support for men and women like Ihar Tsikhanyuk [an openly-gay man in Belarus who was beaten by police for campaigning for gay rights] and to call for justice for all transgender people whose rights are under threat.'

Find out more about Amnesty International UK via their website, amnesty.org.uk.

For a good cause: Stephen and Ade held up boards boasting the evening's reason - to raise money and awareness for Amnesty International

For a good cause: Stephen and Ade held up boards boasting the evening's reason - to raise money and awareness for Amnesty International

Look who's there! Buffy actor Anthony Head was another popular addition to the show, and he posed happily with Mel and Emma

Look who's there! Buffy actor Anthony Head was another popular addition to the show, and he posed happily with Mel and Emma

Ode to Bake Off? Mel looked rather frightened of the corset-inspired cake at the Rocky Horror Show's afterparty

Ode to Bake Off? Mel looked rather frightened of the corset-inspired cake at the Rocky Horror Show's afterparty

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