'X Factor' judge Cheryl Cole reportedly told Simon Cowell off for teasing her about her dress live on air.
During Saturday night's show, Cowell advised Cole that she "better sit up", while she was commenting on one of the performances.
When Cole asked why, Cowell replied: "You'll see why in a minute."
According to the Daily Mail, Cole later slapped Cowell on the leg off-camera.
A source said: "Cheryl was furious that Simon decided to make his remark on live TV, she felt he could have alerted her to the issue with her dress off camera."
