Willoughby kicked off the new series, her first without Fearne Cotton, by sucking a jelly pot into her mouth before leaning over Barrowman and attempting to transfer the dessert directly from her mouth into his.
She narrowly missed, forcing Barrowman to lean over and suck it off the step. He then moved on to his fellow I'm A Celebrity camp mate Emily Atack, who looked disgusted as she attempted to keep the wobbly treat in her mouth.
Take That’s Howard Donald then dropped the jelly onto the face of new Team Captain Paddy McGuinness after missing his mouth.
The upcoming episode marks the start of a new series after Cotton stepped down from the show after 10 years.
She said: “You think it’s going to go on forever and always be there. I knew something was up because she called me and she never calls me!”
Despite being left feeling “sad” at the news, the TV star said she “respects” Cotton’s decision to move on.
The new line-up will welcome new Team Captain McGuinness, who will appear alongside Willoughby for the show's usual string of risky fun and games.
TV presenter Mark Wright also features in episode one and is tasked with guessing the object Willoughby is pretending to be.
Keith Lemon also blindfolds Donald and hits him with random objects.
Celebrity Juice is on ITV2, tonight at 10pm