They may been together for over 20 years now – but the Prince and Princess of Wales’ romance shows no signs of cooling.

On Tuesday afternoon, the royal couple delighted fans when they joined the Duke and Duchess of Edinburgh for the first Buckingham Palace garden party since King Charles’ Coronation. 

After greeting members of the public, Prince of Wales was pictured by a guest lovingly placing his hand on his wife’s back as they returned to the Palace.

The royal fan Instagram account @catherine.princess.of.wales then shared the image with their 177,00 followers, captioning the candid snap: ‘Madly in love.’

With the exception of their 2011 wedding, the couple rarely exchanged such loving gestures in public in the early days of their marriage.

Here FEMAIL reveals how Prince William has become increasingly comfortable in the spotlight in recent years – and isn’t afraid to show his affection for Kate.

Ahead of their nuptials, the Middleton family released a photo of the couple on their graduation day from St Andrews in 2005.

William, 40, and Kate, 41, were both dressed in white shirts and the image showed them holding hands – marking one of the first times the public had seen the couple indulge in any kind of PDA.

In the years that followed, the then Duke of Cambridge appeared proud to have his glamorous wife join him on engagements – but appeared wary of ever indulging in a display of affection.

For instance, Prince William kept his distance on the Warhorse premiere red carpet in 2012 – instead opting to chivalrously hold Kate’s umbrella to protect her black lace Alice Temperley gown.

As they settled into their royal roles, the pair became known for being reserved when it comes to showing their love, particularly during public engagements.

So it’s perhaps not surprising that an image of the couple holding hands at Princess Eugenie’s 2018 wedding to Jack Brooksbank sent royal fans wild.

While speaking to Prince Harry, the then Duchess of Cambridge placed her hand on her husband’s knee in the pews of St George’s Chapel in Windsor – prompting William to lovingly place his on top.

Sharing the moment on Twitter, one fan gushed: ‘William and Kate in rare PDA.’

‘In love,’ another responded. ‘I love this couple!’

The following year, the couple were were filmed holding hands as they boarded a helicopter in the grounds of Kensington Palace to attend an engagement in Blackpool.

At the time, it seemed as though Prince Harry and Meghan Markle’s affectionate displays had rubbed off on the couple – as experts noted how the Duke and Duchess’ PDAs did not follow ‘royal precedent’.

In 2021, the couple returned to St Andrew’s University for a royal engagement – where they treated fans to some more PDA.

While waiting for a yachting lesson to begin, Prince William was pictured placing his hand on his wife’s shoulder on West Sands beach.

The loving displays of affection between Kate and William continued into 2022 when the couple were photographed exchanging kisses on the cheek at the Royal Charity Polo Cup.

The Princess of Wales arrived with the couple’s black cocker spaniel Orla to watch Prince William compete in the annual event.

Following their loving greeting, Prince William was seen putting his arm around Kate as they walked back to their car.

What’s more, Prince William appeared equally as protective of his wife when they greeted wellwishers who left flowers in the Sandringham estate following the Queen’s death in September 2022.

The father-of-three placed his hand on Kate’s back as they returned home – moments after telling a member of the public that he ‘hadn’t processed’ his beloved grandmother’s passing.

Last December, the royal couple jetted out to Boston to attend the Earthshot prize gala. The Prince launched the initiative in 2020 to come up with solutions to combat climate change.

Kate and William’s red carpet appearance was in stark contrast to how they appeared at the Warhorse London premiere 10 years earlier.

As well as holding hands on the red carpet, the pair shared an intimate moment later when they were both seated inside the venue.

William was seen placing his hand on his wife’s back as they leaned together to talk quietly.

The evening before, Kate Middleton had been pictured with her hand lovingly placed on William’s knee as they sat courtside at the Boston Celtics basketball game.

It seems as though 2023 is shaping up to be one of Kate and William’s most loved-up years to date – as they have been pictured indulging in even more instances of PDA during public engagements.

In January, the Prince of Wales placed his hand on his wife’s back as he allowed her to enter the Windsor Foodshare ahead of him.

Last month, the proud husband wrapped one arm around Kate as the pair left The Rectory pub in Birmingham.

Days later, Buckingham Palace released a sweet unseen snap from a family day out to mark the 12th anniversary of their spectacular wedding.

In the portrait, taken by environmental photographer Matt Porteous, the royal couple is seen riding bikes in the Norfolk countryside with their arms around each other.

The image is an outtake from a series that was shared on Mother’s Day and Christmas 2022 – and is now the fourth image the public has seen from this particular day.

It was simply captioned ’12 years’ – with a red heart emoji.

As they arrived at Westminster Abbey for King Charles’ Coronation on Saturday, the Prince of Wales was spotted gazing lovingly at his wife – as Kate looked behind her shoulder to check on Princess Charlotte, eight, and Prince Louis, five.

The historic ceremony took place at Westminster Abbey – where the Prince and Princess of Wales had tied the knot 12 years before.

Despite keeping their distance at the beginning of the Buckingham Palace garden party this week, Kate and William lovingly came together again at the end – suggesting that the royal couple are happier than ever in their new roles.