The U.K.’s Prince William opened up about his family in a candid interview with the comedy duo Declan Donnelly and Ant McPartlin for an ITV documentary. In a sneak peek of the special, the 33-year-old Duke of Cambridge and his 31-year-old brother Prince Harry talked about a number of things, including Prince George and his Princess Charlotte.

“I’m a lot more emotional that I used to be,” Prince William replied when asked how being the father of those two children changed his life. He continued, “I never used to really get too wound up or worried about things but now the smallest little things can get — I can feel — you well up a little bit more.”

According to the Telegraph, Prince William also revealed he sometimes worries about “not being around to see [his] children grow up.”

Prince William lost his mother, Princess Diana, in 1997 when he was only 15 years old.

“But you know, from some of my earliest memories, I remember my mother and father taking us to charities and organizations and showing us, you know, what goes on,” he said during the interview. “And I think it’s seeing such a broad spectrum of life, it’s really important from a young age, to give you a bit of perspective to go, ‘You know, you don’t just live in a palace.’ it's very important you get out and you see what goes on in the real world.”

The father of the two princes, Prince Charles, also will be featured in the ITV documentary. At one point during his interview, the Prince of Wales said he loves being a grandfather, but admitted he’s never changed the diapers of either Prince George or Princess Charlotte.

In an interview with Event magazine, McPartlin spoke about his experience interviewing members of the the royal family and said it was “fascinating” to hear how Prince Charles talked about his grandchildren and his wife Camilla, Duchess of Cornwall.

“When Ant and Dec Met the Prince: 40 Years of the Prince’s Trust” airs on ITV in the U.K. Jan. 4 at 9 p.m. local time.