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

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

The Princess of Wales, 41, visited a Brownie troop in Slough, England, Monday where she revealed 5-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.

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

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

The fun, philanthropic day out comes just two days after Charles’ coronation at 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.

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

While his grandpa was being crowned in the three-hour 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, when he adorably made a series of funny faces during the event, as the Royal Air Force planes soared over the palace.

Meanwhile, Louis was absent from the king’s coronation concert, which kicked off Sunday at 8 p.m. — past his bedtime.

The star-studded concert featured performances from Katy Perry, Lionel Richie and former “Pussycat Dolls” member Nicole Scherzinger.

Perry performed her 2013 hit, “Roar,” which had Charlotte singing along.

Richie’s “All Night Long” also got the royal family up and dancing in their box on Windsor Castle’s grounds.