Prince William and Kate Middleton's Shared 'Naughty' Sense of Humor Keeps Them Close

Prince William and Kate Middleton continue to be a close-knit couple after over two decades of romance, and their unique sense of humor keeps the royal couple engaged.

"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," royal biographer Christopher Andersen told an outlet. "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 have also passed their wacky, slapstick, Monty Python-meets-Benny Hill sense of humor on to the children," Andersen shared. "And like all parents of young children, William and Kate find themselves refereeing when the kids fight over the TV remote, or when the inevitable teasing that goes on between siblings turns into the equally inevitable wrestling match."

William and Kate grew up in active households, and they're continuing the tradition while raising Prince George, Princess Charlotte and Prince Louis.

"Competition runs in the royal blood," Andersen pointed out. "No one enjoyed a spirited contest more than the late Queen Elizabeth II, whether she was cheering on her horse at Ascot or watching a tug of war at the Highland Games."

"Prince Philip was a world champion four-in-hand carriage driver and Princess Anne competed in equestrian events at the Olympics," Andersen shared. "And King Charles was such a passionate polo player he suffered countless injuries in the process."

In Meet Ella, James Middleton revealed William often used his brother-in-law's dog to avoid playing games with the Middletons.

"But the royals look like pikers compared to the Middletons, who taught Kate that winning was pretty much everything," Andersen said. "William and Kate’s card games are so heated and all-consuming that William makes excuses to avoid being sucked in."

"But away from his win-at-all-costs Middleton in-laws, William has never shied away from going up against Kate in a contest," he added.

As Kate focuses on her health journey, the Wales kids are being mindful of the princess' condition.

"But since Kate's cancer diagnosis, the children have been more sensitive to their mother's needs for a little more peace and quiet than usual," Andersen noted. "But their overall family dynamic – the hectic schedule of school, after-class activities, birthday parties, and play dates that fill the calendar — hasn't changed."

"That continuing sense of normalcy has without doubt been key to Kate's recovery," he noted.

The Wales brood is finding their new normal after the Princess of Wales shared that she is now cancer-free. OK! previously reported Kate isn't being pushed to take on public engagements as she focuses on being in remission.

"Kate is on the guest list for this year's Christmas gathering," a source told an outlet. "She's keen to join her children and family to celebrate the holidays, but there's no pressure for her to attend."

"Obviously everyone is looking forward to having her there, but if she doesn't feel up to it on the day, the family will understand," the insider continued.

Andersen spoke to Fox News Digital.