Undercover: Stephen Mulhern
THEY'RE BEHIND YOU! Oh yes they are. Stephen Mulhern was oblivious to Ant and Dec's involvement in this most ambitious Undercover set-up to date.
Watch above as they prank the Britain's Got More Talent host (and friend of the show) good and proper!
Go behind the scenes and see how Ant and Dec set up this epic prank!
See what happened when the boys got inside Jeremy Kyle's ear