Leona Lewis is still close with Cowell, seven years after she parted ways with record label Syco.
The former 'GMB' host called Teigen 'a despicable piece of work who built a career around being married to a pop star'.
Lewis first met Dennis Jauch when he was a backup dancer for her during her 2010 The Labyrinth tour.
Little Mix, Leona Lewis and Alexandra Burke have all enjoyed huge success from X Factor. But what about the others? Find out what they're all up to now.
Leona Lewis has confirmed that she’s joined the mega line-up for the X Factor final, hinting that she’ll be duetting with one of the finalists. Louisa Johnson, who’s already confirmed to be singing with mentor Rita Ora, Ché Chesterman and Reggie ‘N’ Bollie will be battling it out to be crowned X Factor champion this weekend.