Tulisa hits a bum note as her sheer dress leaves little to the imagination on X Factor

By Emily Sheridan

Last updated at 2:37 PM on 28th November 2011

In the last two weeks, Tulisa Contostavlos's arm tattoo has been the focus of attention on The X Factor.

But last night, she unwittingly managed to deflect the spotlight onto her curvy derrière as she ended up flashing it on the live results show.

Wearing a figure-hugging sheer black dress, Tulisa ended up showing off her bottom as she jumped for joy after learning her act Little Mix has progressed to the semi-finals.

Glam: Tulisa Contostavlos looked chic in a fitted black and gold dress at the X Factor results show last night

Oops: The 23-year-old's sheer dress ended up exposing her bottom as she celebrated with Little Mix

Under the bright studio lights, the North Londoner's G-string was clear to see through the sheer material.

Tulisa's over-exposure comes after she declared she would never strip off for a magazine shoot.

She told The Sun: 'I'd never get naked in a mag. I don't care how much money. You can offer me millions.

'I'm not a prostitute. I'm sorry, naked? That's no diss to anyone who does it, but I'm a musician - I'm not selling my body.'

Peachy: The N-Dubz star didn't realise her dress would appear transparent under the studio lights

But when it comes to showing her arm tattoo, Tulisa is determined to carry on her arm salute.

It was reported she was being investigated by Ofcom over suggestions her 'The Female Boss' tattoo was promoting her fragrance.

However, Tulisa said: 'I was showing off my tattoo long before The X Factor. It's always been my trademark and it's always been my nickname.

'The perfume's not actually called The Female Boss - it's just TFB. So someone wouldn't go into a shop and buy my perfume just because they'd seen my tattoo. The show told me it's OK, I can carry on doing it - and I will.'

Celebrate: Tulisa couldn't hide her joy as her girl group got through

Meanwhile, Tulisa laughed off reports she was being romantically pursued by The Only Way Is Essex star Mark Wright.

She tweeted: 'Mark has never texted me and does not have my number.'

Tulisa has been dating her N-Dubz bandmate Richard 'Fazer' Rawson for several years.