The X Factor boss was wound up by the amount of young lads with a guitar auditioning.
“I’m kind of allergic to guitars today,” he tells one hopeful.
Cheryl agrees: “If they carry on at this rate every one will be playing a guitar.”
In a break between auditions, Simon says: “I could merge 50 of these people, they all sound identical.
“I’m going to get 50 guitars, and dynamite and I’m actually going to blow them up.”
And when the next act also turns up with the instrument, Simon ends up smashing a guitar on the floor in anger at the side of the stage.
“I think he’s lost his mind,” says Cheryl.
The X Factor 2014 airs tonight at 8pm on ITV