She's been bonding with her Dancing On Ice co-stars since the competition series returned earlier this month.

And Holly Willoughby couldn't contain her laughter as she secretly recorded a clip of new judge John Barrowman and co-host Phillip Schofield sharing tips on maintaining their grey hair on Sunday.

Uploading the footage on Instagram, the pair were left shocked when they realised the bubbly host, 38, was spying on their conversation, with performer John, 52, cheekily flashing up the middle finger and branding her 'evil'.

The stage actor ran his fingers through his newly-dyed 'do as he spoke about managing his tresses with the nation's most-recognised silverfox, 57, in between rehearsals for DOI.

With a sneering Holly behind the door, John explained: 'When it's wet it becomes luminescent.

'When I put my normal product in it, it makes it look thin as you can see through [the hair strands]. If you use a matte paste...', the Doctor Who host said, before the blonde chimed in: 'This is the greatest conversation I've ever heard.'

The I'm A Celeb star gasped in shock as he playfully swore and shouted: 'You are so evil!' 

In a separate social media post, Holly jumped for joy as she recited a short dance routine alongside panellists John and Ashley Banjo, 31. 

Six contestants skated during last Sunday's launch, with the remaining six taking part this weekend.

During the launch show, Ian 'H' Watkins and Matt Evers made history as they debuted their same-sex partnership on Dancing On Ice, which reduced I'm a Celeb's John to tears. 

Former Blue Peter presenter Radzi Chinyanganya, ITV presenter Lucrezia Millarini, model and businesswoman Caprice Bourret, Love Island's Maura Higgins, blind Paralympic champion Libby Clegg and retired footballer Kevin Kilbane will also make their debuts in front of the judges. 

Holly and Phillip return to host proceedings while judges Jayne Torvill, Christopher Dean and Ashley will be joined by new panellist John, following the departure of Jason Gardiner. 

In addition to her jobs on DOI, This Morning and Celebrity Juice, busy bee Holly is currently working on a mystery project with Dunelm.

Earlier this week, the blonde took to Instagram to tease the production as she posed while a make-up artist touched up her look and member of the wardrobe department adjusted her outfit.  

Giving a hint to fans about the project, Holly wrote in the caption: 'Have a little news coming soon… and it’s the stuff of dreams.'