Kate Middleton reveals Prince Louis’ ‘adorable’ nickname for the first time

Kate Middleton is no longer staying mum on her younger son’s secret nickname.

The Princess of Wales, 41, visited a Brownie troop in Slough, England on Monday where she revealed five-year-old Prince Louis’ nickname for the first time.

“Pop that in the fire, Lou-Bug,” Middleton told Louis as they toasted marshmallows together at the event.

Kate and Louis made the visit with Prince William, 40, Prince George, 9, and Princess Charlotte, 8, following the coronation of King Charles’ over the weekend.

Fans went into a frenzy after little Louis’ nickname was revealed, taking to Twitter to share their excitement.

“Oh God, that’s adorable!” one royalist exclaimed.

“I can’t get over Lou-Bug,” another excitedly wrote.

However, the little prince isn’t the only child in his family with a nickname.

Princess Charlotte is reportedly called “Lottie” by her mom, while Prince George is known as “PG Tips,” according to Harper’s Bazaar.

Prince Louis joined his family for his first royal engagement on Monday. — “Pop that in the fire, Lou-Bug,” Middleton told Louis as they toasted marshmallows together at the event.

Fans went into a frenzy after little Louis' nickname was revealed, taking to Twitter to share their excitement. — Fans went into a frenzy after little Louis’ nickname was revealed, taking to Twitter to share their excitement.

During the visit, Louis, Charlotte and George got to participate in various troop activities, such as making s’mores, playing archery, finger painting, and sanding.

The fun, philanthropic day out comes just two days after King Charles’ coronation ceremony, which took place on Saturday Westminster Abbey.

The historic day marked the official transfer of power to the monarch after the death of his mother, Queen Elizabeth II, last September.

"Pop that in the fire, Lou Bug," Middleton instructed her son as they made s'mores with a Brownie troop Monday. — Kate and Louis made the visit with Prince William, 40, Prince George, 9, and Princess Charlotte, 8, following the coronation of King Charles’ over the weekend.

During the charitable day out, the kids participated in activities like making s'mores and playing archery. — During the charitable day out, the kids participated in activities like making s’mores and playing archery.

Kate Middleton and Prince William took part in the fun on Monday, too.

While the ceremony itself went smoothly, Prince Louis ended up stealing the show, as per usual.

While his grandpa was being crowned in the three-hour-long event, Louis was seen letting out several big yawns. He was also seen waving to onlookers from the car as he pulled up to the Westminster Chapel in the morning.

Last year, Louis charmed royal fans at the Queen’s Platinum Jubilee in June, when he adorably made a series of funny faces during the event, as the Royal Air Force planes soared over the palace.