Prince William
Prince William, Duke of Cambridge (C) meets charity representatives as he attends The Cinema and Television Benevolent Fund's Royal Film Performance 2015 of the new James Bond 007 film "Spectre" at Royal Albert Hall on October 26, 2015 in London, England. Reuters/Chris Jackson/Pool

Prince William shocked many royal fans when he used a mild swear word during a recent interview, which aired on national television.

The Duke of Cambridge and his brother, Prince Harry, recently sat down for an interview with the British comedy duo Ant and Dec as part of an ITV documentary about Prince Charles and the Prince’s Trust foundation. The documentary was aired on national television on Monday, Jan. 5 and also featured interesting stories about Prince Charles from his sons, Prince Harry and Prince William.

It was while Prince William was recounting letters he and his brother received from Prince Charles while they were still studying that he mentioned the word “b-----king,” according to Express. In the interview, the two royal princes shared how they had a hard time deciphering their father’s handwriting that they would write to each other to check what it meant.

"At school, we regularly swapped letters and said 'I think I know what it says can you read it to me?'” Prince Harry said during the ITV documentary. "Just in case it was a b-----king we didn’t know about," Prince William responded.

Although the term "b-----king" may not be a swear word in other parts of the world, in England it is considered a mild expletive. Prince William's use of the said swear word gained mixed reactions from many viewers.

A few royal fans even took to Twitter to post their reactions, Express reports. A Twitter user wrote, "You can tell prince william swears like a trooper when in private #b-----king.” Another Twitter user stated, "Did my ears deceive me?! Did William say "b-----king" - brilliant!"

While many were shocked with the royal faux pas, a few considered Prince William’s candid response as endearing, stuff.co.nz reports.

Twitter user Elliot Gonzales wrote, “Harry and William are coming across as such nice lads in this.” He also stated in his social media post that it was “nice” to hear the two princes “speak so normally.” Meanwhile, Twitter user Charlotte shared how the interview has made her appreciate Prince William and Prince Harry. She wrote, "Just when I thought I couldn't love Prince William and Prince Harry anymore..."

In other news, while 2015 was a memorable year for Prince William and wife Princess Kate, 2016 is also gearing up to be a momentous year for the royal couple. The royal family of four will be celebrating several milestone events this 2016. These include Princess Charlotte’s first birthday on May 2, Prince George’s turning three on July 22 and the royal couple’s India tour in spring. Prince George will also have his first day at nursery school in January.

Apart from these events, the Duke and Duchess of Cambridge will also be celebrating their fifth wedding anniversary on April 29.