Duchess Sophie was one of many royals to make an appearance at King Charles's birthday celebrations on Saturday, looking fabulous in a sunshine-yellow outfit.
As the event came to an end, the royal was seen with other senior members of the royal family waving to crowds from the balcony and watching the flypast of the Red Arrows. As the royals departed the balcony, Sophie was seen supporting Prince William in the sweetest way.
Although the BBC cameras cut away just as William and Sophie re-entered Buckingham Palace, a fan account spotted that Sophie supportively placed her hand on William's back for a fleeting moment.
The royals are known to have a close bond, and in 2023, the pair made a rare joint appearance to attend the premiere of the documentary, Rhino Man, hosted by the Prince's taskforce, United for Wildlife.
The film marked the tragic murder of Anton Mzimba at the hands of wildlife traffickers and follows the training of the next generation of South African wildlife rangers and the crucial role they play in protecting rhinos from poachers and wildlife criminals.
Sophie is known to be particularly close to William's wife, the Princess of Wales, and the duo are regularly seen laughing together at events like Trooping the Colour and Royal Ascot.
HELLO!'s Online Royal Correspondent, Danielle Stacey, said of their bond: "It's no surprise that the Princess of Wales and the Duchess of Edinburgh have such a close relationship. No doubt Sophie has been a huge support to Kate over the years, especially when Kate first joined the royal family in 2011.
"The royal ladies have similar interests and passions, including their love of sport and fashion. They also share common causes within their royal work, with both Kate and Sophie championing the work of children and young people's charities."
With the Prince and Princess of Wales living close to the Duke and Duchess of Edinburgh, it's believed that Sophie has been supporting Kate following her cancer diagnosis earlier in the year.
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