X Factor’s Nick Grimshaw says you can’t hate Simon Cowell “even though you want to”

Clearly the Radio 1 DJ had some ideas of what it was going to be like working with ‘Mr Nasty’ himself, but has found it to be quite different.

“He’s very charismatic, funny and charming. What I have now discovered is that he’s also unruly and naughty!” explained Grimshaw. “It’s like going to work with a toddler or a teenager, it’s constant winding up.”

Grimshaw admitted he’s changed how he approached his role as a judge as a result.

“On day one I was going to be really professional, know what to say to people and make it really succinct and punchy. He doesn’t want that though. He wants it to be anarchic. He’s great, I really get on with him, he’s pretty addictive to be around.”

Of Cowell’s cheeky behaviour, Grimshaw said one of the funniest pranks was on the day new co-host Caroline Flack had to drive the boss to work.

“She came and picked us up and she was nervous because she had to drive a big car with her boss in. Every time she stopped he would put it in reverse, like so sneakily. I was in the back and could see him doing it. So every time we went at the traffic lights she would reverse into somebody!”

“He’s the ultimate wind up merchant,” Grimshaw added.

Not that Grimshaw isn’t guilty of a few pranks himself, stitching up fellow newbie Rita Ora by whispering the wrong information in her ear.

“I’m really enjoying winding Rita up,” Grimshaw admitted. “We had a guy on who was from Tenerife and he sang Enrique Iglesias’s Hero. Half way through he started singing it in Spanish. She was like ‘Where’s Tenerife?’ to me while he’s singing. I told her it’s in the Caribbean and he’s singing in French. So when he ended, she was critiquing him really seriously and was like, ‘You know what babe, you gave a really good performance and when you started singing in French it became better’. Everyone in the arena lost it! I did stitch her up a bit, well 100% not even a bit.”

The X Factor returns Saturday at 8:00pm on ITV

For more head to www.radiotimes.com/xfactor

First look at Nick Grimshaw as an X Factor judge - and we're impressed!