Simon Cowell worried about looking old!

Simon Cowell has refused to rejoin The X Factor UK because it would mean flying back and forth from the US – and jet-lag makes him look OLD.

The guru is a judge on the US version of the show which airs mid-week, making it possible for him to head back for Saturday live shows here.

Strictly Come Dancing’s Len Goodman and Bruno Tonioli do the same weekly commute to appear on both the local and US dance-offs.

There was talk of Simon doing the same for last year’s X Factor live rounds as he had done earlier for Britain’s Got Talent.

But a show source said“Simon hates the way his face looks when he’s jet-lagged and that’s the real reason he will never be back.

“When he’s tired he gets bags and dark circles under his eyes and he hates that.

“The air-con on the plane also really dries out his skin.

“When he gets off a plane he wears sunglasses to hide his eyes.”