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!
Get your funny bone out - it's going to be tickled. Ant and Dec unleash their most elaborate Undercover to date when they trick good friend and fellow presenter Stephen Mulhern on this week’s show!
The TV host was due to take centre stage in panto at The Hawth theatre in Crawley, but unbeknown to him, his naughty pals had a few surprises up their sleeves.
How does Stephen handle it? Watch this promo to see his first reaction, then make sure you tune into this week's show for the whole shebang!
SURPRISE! There's nothing like an episode of Saturday Night Takeaway to bring out an almighty shock. It's normally members of the audience and celeb guests who are the victim of Ant and Dec's hilarious pranks, but remember that you're not necessarily safe at home, so hold that mug of cocoa tight when you settle down on the sofa...
Forget the Oscars, Academy Awards and Primetime Emmy Awards, Neil Patrick Harris is here in ol' Blighty for the most prestigious presenting gig of his career - guest announcing Saturday Night Takeaway of course!
So how do we give Neil a proper British welcome to the UK? Take our just-for-fun poll and let us know!
Just to prove that our glitzy Guest Announcer Neil Patrick Harris is the most well connected man in showbiz, we tried to link him to some of our Saturday Night Takeaway friends and regulars in just six steps. You know what? It was actually pretty easy. NPH will feel right at home when he flies in.
See if you can do it in less...
Neil Patrick Harris to Ashley Roberts in one step...
Neil Patrick Harris cast Nicole Scherzinger in his production of Rent, Nicole Scherzinger was in Pussycat Dolls with Ashley Roberts.
Neil Patrick Harris to Olly Murs in two steps...
Neil Patrick Harris starred alongside Ben Affleck in Gone Girl, Ben Affleck starred alongside Will Ferrell in Jay and Silent Bob Strike Back, Will Ferrell played football against Olly Murs for Soccer Aid.
Neil Patrick Harris to Ant and Dec in one step...
Neil Patrick Harris was once the voice of Bart Simpson, Cat Deeley has just guest starred in The Simpsons, Cat Deeley used to present SMTV and CD:UK with Ant and Dec.
Take a roam around backstage and it's amazing who you bump into at the Saturday Night Takeaway studios... Here's your backstage pass...
Missed out on the solar eclipse due to those pesky clouds?! (We did!) Have a go out our Eclipse Quiz and see if you can identify the sunny celebs hiding behind our Saturday Night Takeaway moons.
Go on, give it go! There's not a grey cloud in sight!
Now that we're over halfway through the current series of Saturday Night Takeaway, it's time to test your knowledge with our Guess The GIF quiz! All you need to do is tell us what happened next.
Go on, aim for 100% - you can do it!