The Princess of Wales was all smiles on Monday afternoon as she attended one of the oldest royal traditions, the Order of the Garter, which is held every year at Windsor Castle.
Kate, 41, watched the historic procession alongside the Duchess of Edinburgh and other members of the royal family, and couldn't help but exchange sweet looks and words with her husband Prince William as he, and other Knights of the Order, processed in front of her.
"Oh, hi!" the Princess could be seen telling her husband as they exchanged looks. Straight after, Kate performed the perfect curtsy for her father-in-law King Charles and Queen Camilla, which she accompanied with the biggest smile. Watch her curtsy in the video below.
It was a very important procession and service this year as it was King Charles' first as sovereign, however, he made the decision not to wear the Sovereign's Mantle – a longer robe with the star of the Order sewn onto the left shoulder.
It was also Prince William's first since he became the Prince of Wales following the late Queen's death.
The event also marked the official installation of two new members to the service.
Former Labour minister Catherine Ashton was made Lady Companion, while Chris Patten, the final governor of Hong Kong, became a Knight Companion.
According to the royal website, "the Order includes The King, who is Sovereign of the Garter, several senior Members of the Royal Family, and twenty-four knights chosen in recognition of their work.
"Knights of the Garter are chosen personally by the Sovereign to honour those who have held public office, who have contributed in a particular way to national life or who have served the Sovereign personally."
It adds: "These have included Marshal of the RAF, Lord Stirrup, and former Prime Ministers Sir John Major and Sir Winston Churchill."