Queen Elizabeth was known for her sense of humor, but she was also not afraid to speak her mind when necessary. And according to one of the Queen's former guardians, she was also willing to engage in mild acts of vandalism.

During an appearance on The Sun's “Royal Exclusive” program, former royal guard Richard Griffin opened up about a particularly funny moment he witnessed in Balmoral, Scotland. The Queen regularly summered at the Scottish mansion and took long walks in the surrounding countryside.

As one of her escort, Griffin accompanied the Queen on many of her walks around Balmoral. On days when there was no filming, the staff would cook a little picnic ... . the two of us would sometimes walk for a couple of hours in the Highlands,” he explained to the outlet.

According to Griffin, Queen Elizabeth especially enjoyed getting “a little peace and quiet” away from her official royal duties. However, that peace and quiet was interrupted “one fine August day” when “a pair of hikers” approached the queen and her guards.

Griffin recalled meeting “an American couple on a walking vacation” who did not seem to know who Queen Elizabeth actually was. 'The American gentlemen didn't recognize the Queen, which is not surprising,' he said. Then they began to tell Her Majesty the Queen that they were from the United States and where they were going next.”

Apparently, when the tourists asked Elizabeth's address, she politely replied, “I live in London, but I have a villa on the other side of the hill.” The villa was, of course, none other than Balmoral Castle.

As the conversation continued, the Queen was asked if she often visited Balmoral Castle. She reportedly told the uninformed visitors, “I've been coming here since I was a little girl, that's over 80 years.”

The American visitors were unaware that they were talking to the monarch, even though she revealed her familiarity with the area. 'If you've been coming here for over 80 years, you must have met the queen. And she said, 'I haven't, but Dick sees her regularly.'”

Griffin made cheeky jokes about Her Majesty, reportedly telling tourists that the queen was sometimes “cantankerous.” Before leaving, the tourists asked for a photo of Griffin and the Queen, which the Queen reportedly found very funny.

“I remember the queen telling me, ‘I hope when he goes back to America and shows that picture to his friends, someone will tell him who I am,’” Griffin explained. Incredible as it may seem, one lucky tourist did indeed run into the Queen in Scotland.