Prince Albert and Princess Charlene have let their guard down for this year's annual palace Christmas party.
The royal couple delighted children at the event as they arrived to the palace courtyard on Wednesday in full holiday garbe. Charlene opted for a cherry red cape, while Albert accessorised a simple suit with an embellished santa hat and spirited (red: garrish!) holiday tie.
The kids "didn't see him and Charlene at first and then when they did, they just exploded. In contrast, Santa himself didn't get anywhere near the same reaction," a party invitee told People about their appearance.
Albert, 59, and Charlene, 39, took in a brief outdoor performance by a local children's troupe of dancers and posed for photos on the Cour d'Honneur stairwell, before retreating to the throne room for a stage magician's performance and a spot of hot chocolate.
The royal couple then treated each child in attendance to a preselected gift.
Prince Albert "is very attached to this tradition, to this way of celebrating Christmas," another attendee told the outlet of the celebration. "It's a lot different way, much less informal, than the way the French, Italians and the Monagasque traditionally celebrate."
"He's just much more American at this time of year."
The royal twins, Prince Jacques and Princess Gabriella, were forced to miss the festive celebration due to colds.
Charlene recently shared an adorable photo of the three-year-old twins posing for a holiday portrait.
In the snap, which was taken by Vanessa Von Zitzewitz, the children pose in front of the Christmas tree as Gabriella holds onto a figurine and her blonde brother beams behind her.
The twins have grown up so much and look super smart in coordinating outfits with Jacques rocking a crisp white shirt and chinos, and his sister in a bright red dress and bow.
"It's starting to look a lot like Christmas. Prince Jacques and Princess Gabriella, December 2017," the former Olympic swimmer captioned the pic on her personal Instagram account.
And in a touching gesture, the twins' half-sister Jazmin Grimaldi, 25, liked the photo.
Jazmin, whose mother Tamara Rotolo had a three week fling with the Prince during a holiday to the French Riviera in 1991, first rose to fame at the tender age of 14 when her father publicly acknowledged her as his daughter.
Flashback! Prince Albert and Princess Charlene give a joint interview before their wedding. Post continues…
It's been an exciting month for the royal family, who celebrated the twins' third birthday on December 10th.
Prince Albert revealed to People they rung in the milestone birthday with two parties, which were "great fun."
Princess Charlene took on the role of party planner and set up "a birthday party with friends they've made at kids' club or the daycare center and their parents," Albert said.
"That was Friday at the big room in the Oceanographic Museum, at this special display they're having for the holidays," he added.
"It's kind of a Polar Arctic setting. There's stuff like mechanised polar bears that move their hands and arms - it was really fun."
"Then we had a little celebration up at Roc Agel with Charlene's family, and that was nice."
So, what do you get a real-life prince and princess?
Albert, whose mother was Grace Kelly, says it was Hot Wheels for Jacques and a Barbie for Gabriella.
But he steered clear of picking a princess barbie.
Explaining, "Let's not overdo the princess thing, okay?"