Earlier this week we reported that winning X Factor Judge Tulisa Contostavlos partied in London to celebrate her PA, Gareth Varey’s birthday, but we can now reveal that Tulisa spent a whopping £9,000 behind the bar that night.

The 23-year-old partied at celebrity hotspot Mahiki in a black and white geometric dress and was also celebrating her book deal which she had signed earlier in the week. A source said

She was delighted to get the book deal and it coincided with Gareth’s birthday, right before Christmas and just after The X Factor – so she could finally let her hair down,

And let her hair down she did! Tweeting:

Eek! Well we can safely say that the X Factor pays well and we will definitely be looking out for job opportunities with Tulisa!