The new judge is said to have upset Cheryl Fernandez-Versini on set when he called her by the wrong name - oops!
According to The Sun, Radio 1 DJ Nick - aka Grimmy - referred to the singer as Cheryl Cole.
Although Cheryl kept her married name after divorcing cheating footballer husband Ashley Cole, she changed it when she married second husband Jean-Bernard.
Perhaps not the best way for Nick to make friends during the second week of auditions!
After one performance, Nick is believed to have said: "Let's go to Cheryl Cole."
The newspaper reports that Nick was then booed and jeered by an audience of 5,000 at Wembley Arena.
And mischievous Simon Cowell encouraged the baying crowd!
Rita Ora, who was sitting in between Cheryl and Nick, is said to have shuffled her chair away from the judges' desk muttering: "I'm backing away..."
Apparently, a miffed Cheryl bit back, saying: "Cheryl. Or Chezza."
Perhaps Cheryl lost her sense of humour after a tough week...
She recently admitted she wasn't sleeping very well, and was this week forced to defend her weight loss - AGAIN! - after her tiny frame came under criticism.
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