Although Prince Charles and Camilla, Duchess of Cornwall, had a good start, the continuation of their relationship was a tough one. But despite everything they have been through, a body language expert revealed that their romance is something "fun, naughty, and spontaneous."

In the celebration of the royal couple's 15th wedding anniversary, they released a playful shot along with their dogs outside Clarence House. Body language expert Judi James told Fabulous, via The Sun, that their snap speaks volumes about the secret of their marriage and relationship compared to other royal couples.

They are both casually dressed and holding their dogs, looking like two happy children instead of being senior royals. Camilla leans in toward her husband, showing a subtle PDA and looking more relaxed than Prince Charles.

The future queen consort holds her dog at ease, while the heir to the throne seems a little awkward clutching his royal pooch. "But the key message from the pose is that it is Camilla who allows Charles to lead an informal, unstuffy, and fun life away from his royal role," James explained.

Prince Charles seems to be "chuckling in delight," and his expression is far different from what the public usually sees. James added that although Camilla shows spontaneity in their photo, it also reveals Charles' cheeky side. It also proves how tune-in she is with her husband and how much comfort and support she gives him.

Their recent snap was a far cry from the strained beginning of Prince Charles and Camilla's relationship following Princess Diana's death in 1997. It took them years before the public accepted their romance. Thankfully, after a few decades, royal fans started to love Camilla and gave her credits for supporting Charles and becoming his rock.

According to Hello! Magazine, the two first met at a polo match in 1970, but their romance ended when he fulfilled his naval duties overseas. Camilla then went on to marry Andrew Parker-Bowles, but she remained friends with Prince Charles. He was even the godfather of one of her two children. They even occasionally met at social gatherings.

Prince Charles then met Princess Diana, and they got married in 1981. However, both of their marriages failed, and Camilla got divorced in 1995. A year later, Charles was officially divorced from Diana.

The future king admitted that he committed adultery with Camilla while he was still married to Princess Diana. They then continued their romance but kept it low-key. In 1999, they made their relationship public and eventually got married in 2005.