King Charles reportedly raised a glass to toast the fourth birthday of his grandson Prince Archie at a family gathering at Buckingham Palace on Saturday 6 May.
The sweet gesture is thought to have been made at a private lunch after Charles and Camilla were crowned King and Queen at Westminster Abbey, the Mail has reported.
Following the ceremony, King Charles and Queen Camilla embarked on their coronation procession back to Buckingham Palace, where they watched the flypast alongside senior members of the royal family, including the Prince and Princess of Wales and their three children, Prince George, Princess Charlotte and Prince Louis.
While the newly crowned royals went on to host a private lunch for members of their family following the Buckingham Palace balcony appearance, the Duke of Sussex made a swift exit when the service finished. Harry, who arrived in the UK on Friday, was immediately taken to Heathrow Airport and boarded a flight back to California, where his wife Meghan Markle and two children, Prince Archie and Princess Lilibet, were celebrating their eldest's fourth birthday.
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Saturday's historic event marked the first time Harry was reunited with his family since the release of his explosive Netflix docuseries last December and tell-all memoir, Spare, published in January.
While the father-of-two visited the UK for a hearing at the High Court back in March, HELLO! previously reported that it was unlikely he saw his brother, Prince William, nor Princess Kate during his time back in Britain. At the time, the Prince and Princess of Wales were away for the Easter holidays with their three children, Prince George, Princess Charlotte and Prince Louis.
Harry, who donned a morning suit for the ceremony, was seated in the third row, alongside Princess Eugenie and Jack Brooksbank, and even shared a sweet moment with his aunt Princess Anne, who was sitting in the row in front.
He smiled at guests and looked in good spirits upon his arrival, walking into the Abbey along with Princesses Eugenie and Beatrice, and their husbands. Harry's reaction to the arrival of King Charles was also caught on camera.
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The historic ceremony saw King Charles and Queen Camilla anointed and crowned in front of 2,300 guests at the country's first coronation to be staged for 70 years.
Starting at 11am, the ceremony included various stages before the Archbishop of Canterbury crowned the royal couple. Read about the full service and crowning, here.
During one special moment during the service, the Prince of Wales performed his ceremonial duties before his father. The King looked touched as his eldest son, Prince William, approached him after he was crowned, reciting: "I, William, Prince of Wales, pledge my loyalty to you and faith and truth I will bear unto you, as your liege man of life and limb. So help me God." The father-of-three then bent down to kiss King Charles in an emotional moment.