The audience at this weekend's X Factor final will see Louis Walsh and Simon Cowell mercilessly mocked as they get a sneak peak of the comedy musical poking fun at the show.
Llouis is portrayed doing Irish dancing in his dressing room, and surrounded by posters of Westlife, in the trailer for I Can't Sing - The Musical.
And show boss Simon is seen hoisting the waistband of his trousers up high, toying with a disposable nappy and popping on his sunglasses with a picture of Sinitta attached to his mirror.
The minute-long film is being played to fans who are seated at Wembley Arena, from where the show is being broadcast live on Saturday and Sunday evenings.
It also focuses on another judge in the show called Jordy, based on former X Factor panellist Cheryl Cole, who is seen getting roses tattooed on her back before blasting herself with two cans of hairspray.
The musical, which opens in February with Nigel Harman as Simon, has been created by comic Harry Hill, who also stars in the ad.
Simon's firm has helped to finance the production which will be staged at the London Palladium.