News Prince William and Prince Harry Open Up About Princess Diana's Parenting Style For the First Time By Jennifer Drysdale 6:59 PM PDT, July 8, 2017 Getty Images Prince William and Prince Harry are opening up about their mother's parenting style for the first time. The royals appear in an upcoming documentary for ITV and HBO titled Diana, Our Mother: Her Life and Legacy, in which they discuss the unique way in which the late Princess Diana raised them. RELATED: Prince William and Prince Harry Say They 'Couldn't Protect' Their Mom Princess Diana From Death"This is the first time that the two of us have ever spoken about her as a mother,” 32-year-old Harry shares in a promo clip for the project, calling her "one of the naughtiest parents." "She was very informal and really enjoyed the laughter and the fun," 35-year-old William adds. "She understood that there was a real life outside of Palace walls.""She was our mum. She still is our mum. And of course, as a son I would say this, she was the best mum in the world,” Harry continues. "She smothered us with love, that’s for sure." RELATED: Prince Harry Recalls Having to Walk Behind Princess Diana’s Coffin: No ‘Child Should Be Asked to Do That’William and Harry recently rededicated their mother's grave in honor of what would have been her 56th birthday. See more in the video below. How Prince William and Prince Harry Are Honoring Princess Diana on Her Birthday This video is unavailable because we were unable to load a message from our sponsors. If you are using ad-blocking software, please disable it and reload the page.