During official engagements, the Duke and Duchess of Cambridge rarely indulge in public displays of affection. Prince William may sometimes place a tender hand on Kate's back, or hug her closely at a celebration, but this isn't usually the norm as is expected of royals.
Onlookers were then thrilled to hear William and Kate call each other by their nicknames "darling" at the Chelsea Flower Show on Monday, when the royals were making their debut as a couple.
The Prince was overheard asking Kate if she could make her own poppy while they knelt to admire the 5,000 Poppies project – a stunning display of 300,000 knitted flowers laid out in the grounds of the Royal Hospital Chelsea.
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William and Kate made their debut as a couple at the Chelsea Flower Show
One of the designers Margaret Knight told reporters: "William asked Kate, 'Could you make one of these, darling?'"
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The Duchess said that she liked the "fluffy ones" made of felt and said "Well done, I'm so impressed with this" as she laid her own knitted poppy down.
"Could you make one of these, darling?" William asked his wife as they viewed a knitted poppy display
William and Kate, who were joined by Prince Harry at the flower show, then moved on to inspect the Support the Husqvarna Garden, which was shipped from Melbourne, Australia. Designer Mick Conway noted how the royals affectionately addressed each other.
"They seemed very interested in the garden," said Mick. "William in particular, he said, 'This for me is gold by far.' He also asked what this plant was (pointing to a Buxus) and Kate said to him, 'Darling, we've got that.'"
The couple were joined by Prince Harry
The royals also had the chance to view a flower – a pink and green Rossano Charlotte chrysanthemum – named after their little girl Princess Charlotte. It is being sold for the first two years through Waitrose with part of the proceeds going towards East Anglia's Children's Hospice, the charity of which Kate is patron.
William asked where they were available and joked, "You could always steal one off the exhibit!"
Kate replied: "Waitrose are selling them!"
William and Kate also viewed a flower named after their daughter Princess Charlotte
Clearly in a jovial mood the Prince asked Alison and John Peace from the Chrysanthemum Society if they could spell chrysanthemum. "I can't even say it," he laughed.
Kate asked, "Do you have a favourite? You don't have to be biased" while Prince Harry pointed at the centre of the display and joked, "What about the one that's in the middle?"
The trio were joining the Queen and other members of the royal family including Sophie Wessex, Princesses Beatrice and Eugenie and Princess Anne on the opening day of the flower show. The Queen, who is patron of the event, is a regular fixture alongside Prince Harry.