The prince and pop star attended the Royal Marsden Trust reception.
The 4-year-old royal cheered on his dad, Prince William, during a Polo match in England.
Plus, did the duchess break royal protocol by baring too much skin at the queen's birthday celebration, the Trooping the Colour parade?
Prince George may be the future King of England, but to Savannah Phillips, he's just a pesky 4-year-old.
The Duke of Cambridge was living his best life on Wednesday.
The Duke of Cambridge was also joined by his cousin, Princess Eugenie, who is preparing to get married in September.
The early birthday celebration marked the Duke of Sussex's first royal engagement since saying 'I do' to Meghan Markle over the weekend.
ET also has new details from inside the newlyweds' regal receptions.
From celebrity guests to the Duchess of Sussex's dress, ET provides live updates of all the must-see moments from their nuptials.
Some viewers of the nuptials thought the seat was left empty in honor of the late Princess Diana.
Harry is going a different route than his older brother, and will exchange rings with bride Meghan Markle at the royal wedding on Saturday.
The Duchess of Cambridge is ready to watch Prince Harry and Meghan Markle say 'I do!'
The royal groom arrives to Windsor Castle with his brother and best man by his side.
Their 3-week-old little brother, Prince Louis, was not expected to attend the wedding.
