Royally Obsessed: King Charles and Queen Camilla Are 'Deeply Competitive' Over This Quirky Secret Hobby

King Charles III, 76, and Queen Camilla, 77, developed numerous passions and shared interests in the past half a century the pair have known one another. This led Her Majesty's son, Tom Parker-Bowles, 49, to share their secret hobby and "deeply competitive" streak with Fox News.

Their Majesties enjoy "mushroom hunting" together, which led Parker-Bowles to share, "They call it 'the silent hunt.' In Italy and… in a lot of places all over the world, the wild harvest of mushrooms is amazing. Up in Scotland, around the beginning of fall, you get the most amazing mushrooms. You get these… lovely, beautiful, meaty mushrooms. You get chanterelles [which are] bright yellow and scented like apricots – it just tastes so good."

The food critic and author of Cooking & the Crown added, "And we go looking. The king is a great mycologist, or mushroom expert. And my mother also loves doing it. So off they go with their baskets separately, and they get quite competitive… they’re both very good. And of course, they’re always taken straight to the kitchen, and we have them with pasta."

The King has long been known not only as a conservationist but also for his extensive gardens on his private estates.

Parker-Bowles continued, "In the days of [King] Edward, of course, there weren’t fridges, there weren’t strawberries flown in from all over the world. You ate what was in season. And yes, the king is an expert gardener, an expert mushroom picker. He has many, many strings to his bow…. He can tell you about any mushroom. And he knows which ones are poisonous."

"The king doesn’t eat lunch," Charles III's former press secretary, Julian Payne, once spilled. "So, an early lesson I learned when out on the road with him was to have a big breakfast or bring a few snack bars with you to keep you going. The working day is pretty relentless," he added. "Beginning with the radio news headlines and a breakfast of seasonal fruit salad and seeds with tea."

Just like his father, at the age of 42, William is health conscious, which is also a trait he shares with his wife, Kate, Princess of Wales,42 . Both millennial royals are avid fans of exercise and prefer to indulge in sweets or junk food less than a handful of times per month. When it comes to sports, the future queen enjoys tennis, while the future king is said to have a passion for football and rowing.

The king-in-waiting's mother, Diana, Princess of Wales, also loved physical activity, with tennis and gym exercise being her two favorite ways to work up a sweat. Once the late royal conquered the eating disorder bulimia nervosa in the early '90s, she added healthy fruits, lean poultry, and vegetables to her daily diet.