Queen Elizabeth may be the world’s ­longest-reigning ­monarch, serving amid a lavish life of luxury, but at heart she’s fun-loving, frugal and loves her guilty pleasures, reveal!

While presenting a picture of elegance and devotion to duty in public, palace insiders claim the queen lets loose behind the scenes — drinking, gambling and cutting the rug with her longtime love, Prince Philip! Click through Radar’s gallery to find out more surprises about Queen Elizabeth’s secretive side.

Queen Elizabeth may be the world’s ­longest-reigning ­monarch, serving amid a lavish life of luxury, but at heart she’s fun-loving, frugal and loves her guilty pleasures, RadarOnline.com can reveal! While presenting a picture of elegance and devotion to duty in public, palace insiders claim the queen lets loose behind the scenes — drinking, gambling and cutting the rug with her longtime love, Prince Philip! Click through Radar’s gallery to find out more surprises about Queen Elizabeth’s secretive side.

SOURCE: GETTY IMAGES

Former royal chef Darren ­McGrady, who worked for Her Majesty and her family from 1982 through 1993, revealed, “She likes a gin and Dubonnet. That’s her f­avorite drink.” Royal snitches say Elizabeth has also been known to indulge in dry gin martinis, sweet German wine and even champagne before bed.

Even more shocking, the queen has made millions off the ponies!

Her Majesty has always shown a keen interest in horses and ­inherited several thoroughbreds following the death of her father, King George VI, in 1952. But in the last three decades, figures from the British Horse Racing Authority show she’s won a stunning $8.8 million in horse-racing prize money!

That haul, in addition to her already staggering fortune — ­rumored to be worth hundreds of millions of dollars — still doesn’t mean the queen is a big spender, especially when it comes to her household! “The chefs and food and kitchens come last. They’re still ­using pots and pans from the 1800s, with the Queen Victoria stamp on them, at Buckingham Palace,” dished McGrady, who noted the thrifty royal would rather spend her spare cash on horses.

SOURCE: GETTY IMAGES

Seeing her draped in jewels during public appearances, it may be hard to believe the 91-year-old head of the House of Windsor is actually a penny-pincher. But courtiers insist she often wanders the palace turning off lights to save electricity. “Sometimes she goes from room to room, turning off lights. Often huge palace rooms have only one light on,” said a former royal aide. “And for all the chandeliers in the palace, you never see any of them lit up except on special ­occasions.”

“She’s very frugal about food, too. Tonight’s roast is tomorrow’s sandwich, that sort of thing,” noted the former royal aide, who said the queen has no problem eating leftovers and has even been spotted at the drive-through at McDonald’s! In fact, Elizabeth even owns one of the fast-food franchises in Banbury Gateway Shopping Park, about 80 miles northwest of London. “She is such a fan of chocolate, don’t be surprised if you ever see the queen enjoying a McDonald’s shake with some fries!” said an insider.

SOURCE: GETTY IMAGES

Despite having staff who tend to her every need, the queen has been seen shopping for groceries and visiting the local fish market. Some sources say she even clips coupons. The cost-cutting move calls to mind her days as a young bride-to-be, when thrifty Princess Elizabeth saved up ration coupons to purchase the fabric for her wedding dress in the lean days following World War II.

SOURCE: GETTY IMAGES

On Nov. 20, the queen and her devoted consort, Prince Philip, 96, celebrated their 70th wedding anniversary. Amid decades of scandal and tumultuous change, their love has endured — due in no small part to Elizabeth’s carefree personality and good-natured spirit. The royal couple was even famously photographed square dancing during a tour of Canada in the ’50s.

SOURCE: GETTY IMAGES

Elizabeth is said to adore show tunes — especially those of Richard Rodgers and Oscar Hammerstein II — and considers a ditty from Oklahoma! to be her and ­Philip’s “song.”

SOURCE: GETTY IMAGES

According to Ingrid Seward, author of The Queen’s Speech, her favorite, “which she and Prince Philip used to dance to when they were engaged, is ‘People Will Say We’re in Love.’ She loves all the musicals,” said Seward, who also claimed Elizabeth has a penchant for pudding!

“She loves chocolate,” Seward noted. “She has got a sweet tooth and has to curb it.” Former first lady Michelle Obama confirmed the lowbrow menu option and says, “I do ­remember ordering French fries at the palace. They were good — they were some good fries at the palace.”

Aside from scarfing down junk food, the queen is also a cutup and an excellent imitator! “She is quite deadpan and yet has a wonderful rollicking sense of humor,” insisted her cousin ­Margaret Rhodes. “When Concorde used to fly over Windsor Castle, she developed an ability to mimic Concorde,” said Sally Bedell Smith, author of Elizabeth the Queen: The Life of a Modern Monarch. The down-to-earth sovereign may live in a castle, insiders said, but she still walks her beloved pooches herself, drives her own car around town and cruises through Mickey D’s. Who knew we were all living like royalty!