The Duchess of Cambridge and Prince Harry, who seem to have struck a particular bond since her wedding to Prince William last year, looked like they were having a whale of a time as they chatted to the London 2012 stars.
Clearly enjoying his sister-in-law's company, Harry was spotted smiling and laughing with Kate during their afternoon out, where they chatted to triathlete Jonny Brownlee, plus rowers Andy Triggs Hodge, Sophie Hosking and Kat Copeland.
Afterwards, gold medal winning Copeland gushed of coming face-to-face with Kate Middleton: 'I've wanted to meet her, all through the Games I've seen her at other sports and I keep missing her. She's gorgeous in real life.
'They were both really nice. Kate had obviously watched all of our races, which was pretty amazing.
She added: 'Both of them seem really enthusiastic and excited, they know a lot and they've obviously watched it all.
'She was really knowledgeable about our sport and we talked about the cycling and she talked to Brownlee about the triathlon so it's pretty incredible that they have been watching everything and they really know what's going on.'
On Wednesday, Kate dressed down to cheer on Team GB's Women's hockey team at the Olympic park, dressed in her best off-duty attire: a pair of relaxed skinny jeans, a white t-shirt and a sophisticated Smythe blazer.
Kate Middleton, Prince Wiliam and Prince Harry are all expected to attend the Olympics closing ceremony on Sunday.
Have you enjoyed Kate Middleton and Prince William's Olympic appearances? Have they done a good job as London 2012 ambassadors? Let us know in the comments box below…