Princess Charlene of Monaco and Prince Albert II mingled with racing royalty Max Verstappen at the Monaco F1 Grand Prix reception yesterday evening.The group gathered for the glamorous affair marking the 83rd Monaco F1 Grand Prix at the Oceanographic Museum, a marine sciences museum in Monaco City.The mother-of-two, 48, beamed in an emerald dress as she posed for photographs with her husband, as well as the four-time Formula One winner and his model girlfriend, Kelly Piquet, whose father is celebrated racing driver, Nelson Piquet.Albert and Max both looked smart in navy suits, while Brazilian model and columnist Kelly donned a mid-length dress in the very on-trend chocolate brown shade.Less than 24 hours later, Charlene and Albert arrived in the paddock today, the exclusive backstage area located behind the pit lane.Charlene once again looked striking in an elegant pleated red dress, matching slingback heels, and black shades, while Albert opted for a more casual look with a baseball cap and mismatched suit pieces.The racing event, which runs until Sunday, attracts stars from across the globe, this year including Emily in Paris actress Lily Collins and Princess and Junior Andre.The Monegasque royal couple have enjoyed a busy itinerary recently, and on Monday, they greeted King Felipe VI of Spain during a historic meeting in Madrid. Princess Charlene and Prince Albert II accompanied by Max Verstappen and Kelly Piquet at the reception of the 83rd Monaco F1 Grand Prix held last night at the Oceanographic MuseumOn Monday, Charlene, 48, and her husband, Prince Albert, were welcomed by Felipe and Queen Letizia at the Palace of Zarzuela in the Spanish capital for their first-ever official visit.Marking a significant diplomatic milestone for the Monegasque royal couple - all eyes were on the group as they began a tour of the city's Royal Botanical Garden.Yet eagle-eyed onlookers suggested that Charlene may have made an unfortunate protocol breach during the poignant meeting - by curtsying to both Felipe and Letizia.'Princess Charlene's protocol error: Although the title is that of Princess, she is the consort of a head of state, therefore, she should not curtsy to the Kings,' noted one X user.Meanwhile, another Instagram commenter criticised the royal for 'making an absolutely incorrect curtsy' and leaving members of the public 'perplexed'.However, others online came to Charlene's defence and suggested that it was not, in fact, a protocol error, and that the 'perfect' princess had indeed been acting in line with royal etiquette.'It is not the same to be "His/Her Serene Highness" as it is to be "Majesty", it's a higher rank,' wrote one user, while another added: 'They are neither royal highnesses; therefore, Charlene's reverence is perfect. 'While Charlene's alleged protocol breach remains widely disputed, the event is not the first time the royal has been criticised for going against traditional etiquette and formalities. The mother-of-two looked elegant in a pleated red dress as she arrive at the racing event on Friday Pictured: Prince Albert and Princess Charlene in the paddock at F1 Monaco Grand Prix, Monte Carlo in Monaco todayIndeed, in 2019, Charlene herself admitted that she struggles to keep up with the abundance of protocol rules and restrictions - and often finds it confusing.Speaking candidly about the realities of royal life, she confessed to Rapport in 2019: 'I address royals incorrectly, or often curtsey to those I shouldn't be curtsying to, or I forget to curtsy'.However, while some may have perceived Charlene's curtsy as a faux pas, the first day of her and Albert's two-day Spanish visit was said to have gone incredibly well - and helped to strengthen ties between the two nations.The possible protocol breach comes just days after the royal household shared an unseen photograph of Charlene with her arms wrapped around her 11-year-old twins, Princess Gabriella and Prince Jacques.Captioned 'wishing all moms a Happy Mother's Day', the image offered a rare insight into the lives of the two young royals, who are largely kept out of the spotlight despite being members of the Monegasque royal family.Coordinating for the special occasion, Charlene was dressed in an off-white jumper, while Jacques opted for a white crew-neck and Gabriella showcased a sparkly white dress.Images from the same photo shoot were previously released on December 10 in honour of the royal twins' 11th birthdays, with adorable portraits showing the youngsters looking the spitting image of their former Olympian mother.