The mum-of-four's boob escapes out of her tight top
The 32-year-old had squeezed her cleavage into a tight neon green and black outfit but exposed a little too much during an energetic routine at London’s Hammersmith Apollo.
Aside from Blue, the groups’ comeback journeys have all been charted for hit ITV show The Big Reunion.
Kerry admitted on screen that she’d had a difficult time since leaving Atomic Kitten in 2001, talking about her split from ex-husband Brian McFadden, drugs and having bipolar disorder.
She told her Twitter followers yesterday that she was dedicating her performance to her four children.
‘#BigReunion doing this for all my beautiful babies just wanna make them proud xxxxx,’ Tweeted Kerry.
The Big Reunion concert will be shown on ITV2 on 28 March and Atomic Kitten will take part in the show’s arena tour in May.
SEE PICTURES Kerry Katona and Ashley Cole party with stars in London