The 28-year-old singer celebrated her live performance on the X Factor last night by heading to London’s Shoreditch House with her boyfriend John Mayer, and didn’t emerge from the venue till the early hours of this morning.

Depsite it being cold and wet in the UK, Katy made the most of her curvaceous figure and wore a Sєxy black satin corset which she teamed with a black and gold glittering pleated skirt.

The ‘Teenage Dream’ singer completed her look with a pair of black тιԍнтs and thigh-high boots as well as a Chanel handbag as she partied the night away with her musician boyfriend.

Katy accessorised her look with bright red lipstick and a thick gold chain, and was more than happy to speak to fans as she left the trendy nightspot.

She took a liking to one fan in particular and was seen hugging him and posing for pH๏τos before jumping into her waiting vehicle and heading back to her H๏τel with John.

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The singer, who is currently on the European leg of his own tour, looked less keen to be pH๏τographed and quickly made his way to car wearing blue jeans and an unusual brown jacket.

However, it wasn’t as wacky as the outfit that his gilrfriend had modelled earlier on in the night when she performed to a packed-out crowd at Wembley Arena.

Performing her new single ‘Roar’ infront of the X Factor contestants and the famous judging panel, Katy flashed the flesh in a black and orange tiger print dress which showed off plenty of cleavage as well as legs.

The US star is currently promoting her latest album ‘Prism’ which is out this week.