The 23-year-old was out at the Smash and Grab night at Punk nightclub in Soho last night.
She left with Paul Weller's son Nat at Punk, drinking lots of champagne and getting out on the dance floor with a few of her friends.
But things turned bad when she spotted a gossip columnist and made a bee-line for her.
A source said: 'Kelly was dancing with a female friend, then saw someone she knew and went and started talking to them. She sat down next to the girl and looked like she was telling her off. I heard her say "you better watch your back, She then slapped her around the face and stormed out of the club. It was particularly funny as she had a black eye".
It seems Kelly is having a bit of a rough week. I wonder what is going to happen next!!!!