During an interview with host Scott Mills, William revealed the pair watch 'a lot' of children's programmes with Fireman Sam being George's favourite. He added that the Prince will often get annoyed if either of his parents aren't giving the show their full attention.
When asked if George was a fan of Peppa Pig, the pair claimed he's 'gone past' liking the show but they were preparing to go through the obsession again with Princess Charlotte. Their youngest child will be turning two on 2nd May.
Like many couples, they enjoy a box set 'once the kiddies were in bed' and revealed they were particularly keen on Homeland and Game of Thrones. No box set night is complete without a takeaway and the pair admitted they were 'absolutely' allowed to order them, with Kate's go-to choice being a curry.
Asked what William got for his grandmother, the Queen, who celebrates her birthday today, he revealed the 91-year-old is difficult to buy for. However, now he's a father his go-to is homemade gifts from George and Charlotte, with their arts and crafts always going down a treat.
During their surprise appearance, they even had the chance to put their presenting skills to the test by introducing the Top 40 Official Chart with Greg James.
The royals were at the station to promote their campaign, Heads Together, which aims to end the stigma around mental health. The Duke and Duchess have partnered with Prince Harry on the project, who just this week spoke out about the therapy he received to cope with the death of his mother.
The campaign was also chosen as the Charity of the Year for this year's London Marathon, which is taking place this weekend.