Prince William's playfulness is natural.

According to recent reports, the Duke of Cambridge made a "filthy joke" when he delivered his best man speech at Prince Harry and Meghan Markle's royal wedding reception. However, this playfulness has always been a part of him. As a child, there was a time when Prince William used his mom, Princess Diana, as bait to prank the press.

According to Ken Wharfe, Princess Diana's former personal protection officer, her eldest son carried out a practical joke while they were enjoying a holiday in Necker Island at Richard Branson's private retreat. The second-in-line to the throne reportedly told Princess Diana to pose for a photocall to dupe the press before he fired water balloons at them.

The late Princess of Wales initially turned down her son's proposition. But Princess Diana changed her mind when the manager presented her sons with large catapults. They then proceeded with their plans to prank the press.

"William said, we can go to the top of the cliff and when mummy does the photo call we can fire the balloons at the press," Wharfe told Robert Jobson's Royal Podcast (via Express).

As the press drew near, Prince William and Prince Harry launched water balloons and scored a direct hit on esteemed royal reporter James Whitaker.

"It was probably some of the best pictures ever taken of Diana in the Caribbean," Wharfe added.

Prince William and Prince Harry remain indifferent to the press. The royal princes reportedly partly blame paparazzi for the death of their mother.

"I think one of the hardest things to come to terms with is the fact that the people that chased her into the tunnel were the same people that were taking photographs of her while she was still dying on the back seat of the car," Prince Harry told BBC in 2017 to mark Princess Diana's 20th death anniversary.

"She had quite a severe head injury but she was very much still alive on the back seat. And those people that caused the accident, instead of helping, they were taking photographs on the back seat, and then those photographs made their way back to news desks," Meghan Markle's husband added.

Prince Harry opted to snub the press when he tied the knot with Markle. The Duke and Duchess of Sussex only invited one reporter and four photojournalist.

"Harry's attitude towards the press is he doesn't like the press," said Duncan Larcombe, who covered Prince Harry for over a decade as The Sun's royal editor. "The chance of leaving journalists out in the street for the royal wedding is a gift for him."