The Girls Aloud singer's manager Will.i.am revealed she has become close to Paula just a few days after meeting her.
And the Black Eyed Peas star said the pair have hatched a plan to give Simon, 51, some abuse.
According to British newspaper The Sun, he said: 'They worked out pretty quickly that it's funny to annoy Simon, but even funnier if they gang up and do it together.
'Simon used to have Cheryl to put up with on The X Factor and Paula on American Idol, but now he has to cope with them together.
'They are not letting him have an easy ride, but he loves it really.'
Will also suggested that Geordie Cole, 27, and Cowell might return to the British version of the talent show.
He added: 'It would have been impossible for them to do it this year, but I wouldn't rule out Cheryl and Simon both returning. The UK X Factor is Cheryl's first love.'