The royals have been out in force to celebrate King Charles III's Coronation, and it's been one hectic weekend for some of the youngest members of the family. Prince George, 9, Princess Charlotte, 8, and 5-year-old Prince Louis joined their parents for a surprise appearance at this year's Big Help Out event on bank holiday Monday, and we even got a sweet glimpse into their family dynamic by way of Louis' adorable nickname.

While the Prince and Princess of Wales enjoyed activities at the 3rd Upton Scout Group in Slough a they helped renovate the scout hut, Louis joined in with toasting marshmallows over a fire. In a video, posted on TikTok by the Daily Mail, he was handed a stick to add to the flames and Kate Middleton could be overheard saying: "Pop that in the fire, Lou-Bugs." The nickname is seriously cute, although not the only term of endearment we know the parents use for their children. In 2019, the Duchess of Cambridge revealed she calls Princess Charlotte, "Lottie".

The occasion marked Louis' first official royal engagement, and it's safe to say he made quite the impression. His meme-worthy facial expressions during the Coronation ceremony melted the nation's heart as he sat alongside his sister, who wore a matching flower crown to her mum, as they watched George play an important role as second in line to the throne. Louis skipped the Coronation concert on Sunday, 7 May, but his siblings got into the celebratory vibes as they watched the likes of Lionel Richie, Katy Perry, and Take That perform. We bet Lou-Bugs got a good night's sleep after his big weekend!