Kate Middleton And Prince William Reportedly Bonded Over One Cheeky Thing When They Began Dating

William, Prince of Wales, and Catherine, Princess of Wales, are famously conservative in public but, behind closed doors, sources report that the pair bond over a surprisingly naughty sense of humor.

"William once described Kate's sense of humor as 'naughty' and his own as 'dirty,' and claimed that it was one of the most important things that drew them together," explained Christopher Anderson, author of The King: The Life of Charles III, in an interview with Fox News Digital. "They've certainly cleaned up their act for the children's sake, but they can still make each other double over laughing."

William and Kate are famously reserved when it comes to PDA, and while their marriage appears close and happy, they rarely are demonstrative in front of the cameras. So the reveal about a shared sense of humor provides a glimpse into the personal lives of a very public couple who have nonetheless retained a distinct separation between their public royal personas and their private selves. As with their rare moments of public affection, it's a glimpse of how the pair are with one another — and how they are with their children.

"William and Kate have also passed their wacky, slapstick, Monty Python-meets-Benny Hill sense of humor on to the children," observed Christopher Anderson in his Fox News Digital interview. The couple's youngest son Prince Louis has been photographed during cheeky moments at royal events. This famously includes sticking his tongue out at his mom during Queen Elizabeth II's Platinum Jubilee, and it may be why we rarely see the young prince in public.

But Catherine, Princess of Wales, seems well-skilled at managing her mischievous youngsters. In "Gilded Youth: An Intimate History of Growing Up in the Royal Family," author Tom Quinn reports that Kate was widely praised by experts for the way she gently and firmly redirected Louis during the public event (via She Knows). "Kate and William, along with [the nanny], are strict with the children but have this magic ability to appear not to be," a source told Fabulous, per The Sun.

Still, according to Andersen, it's Princess Charlotte who is best at reining in Louis' theatrics. "Big sister Charlotte is the 'Louis-whisperer' in the family," he told Fox News Digital. "She is best equipped to get her rambunctious little brother to behave when — as the youngest child in the family often does — Louis goes off the rails to get attention."