The Duke of Cambridge was in Cardiff hosting a reception for injured rugby players and their families when he made the sweet comments about his family life.
Talking about Princess Charlotte, Prince William said: '[She is] very sweet, but all fathers say "just you wait, when you get to nine, 10, 11 they go crazy." I'm looking forward to it, there will be some drama.'
William also joked that Prince George, who started nursery this year, and Charlotte are already a handful.
'No broken bones yet, but they're trying,' he said. '[They're] running around, pushing things, jumping. Please tell me it gets easier.'
The second in line to the throne flew to Wales for the reception from Norfolk, after working shifts as an ambulance pilot from Monday to Thursday.
He told the BBC: 'I love my rugby. Having lived in Wales for four years, worked here and seen the rugby I'm thrilled to be back. When the Welsh anthem goes, you know you are in Cardiff.'
Despite dividing his time between his job, royal engagements and his family, Prince William was recently accused of being 'lazy', and criticised for only having attended two royal engagements this year.
He will soon be heading to India and Bhutan with wife Kate in April for a six-day visit, while Prince Harry will be visiting Nepal in March.
The Duke and Duchess of Cambridge will visit #India and #Bhutan this spring between the 10th - 16th April. "The Duke and Duchess are very much looking forward to their tours of India and Bhutan. Their visit to India will be an introduction to a country that they plan to build an enduring relationship with. They will pay tribute to India's proud history, but also are keen to understand the hopes and aspirations of young Indian people and the major role they will play in shaping the 21st century. Their visit to Bhutan will allow them to continue a relationship between two Royal Families by meeting The King and Queen. The Duke and Duchess have heard many wonderful things about the country and are grateful to have this opportunity to get to know the Bhutanese people. This tour, coming shortly before The Queen's 90th birthday, will also allow The Duke and Duchess to pay tribute to Her Majesty's huge contribution to diplomacy in Britain and the Commonwealth." Image Â© Press Association
Before William's lovely comments about his children, George and Charlotte's mum had also recently talked about them in the blog post she wrote for the Huffington Post during her stint as a guest editor, where she revealed they're encouraged to talk about their feelings.
'Like most parents today, William and I would not hesitate to seek help for our children if they needed it', she wrote.
'We hope to encourage George and Charlotte to speak about their feelings, and to give them the tools and sensitivity to be supportive peers to their friends as they get older. We know there is no shame in a young child struggling with their emotions or suffering from a mental illness.'