Simon Cowell was not a fan of this prank, but Heidi Klum made the most of it.

Simon Cowell has refused to change his look for almost a decade, despite having close friend Heidi Klum on hand to help.

Simon Cowell is terrified of having close friend Heidi Klum change his long standing screen look - for fear of her dressing him in rhinestones. German supermodel Klum revealed that Cowell has ducked the opportunity to ditch his favoured items of t-shirt and jeans alongside her for almost a decade.