Meghan Markle and Prince Harry's on-stage kiss at Invictus Games was rare sign of affection. Why we seldom see royal PDA.

Prince Harry and Meghan Markle offered a sweet and rare display of public affection during the opening ceremony for the Invictus games on April 16.

Markle wore an off-the-shoulder Khaite bodysuit and high-waisted trouser as she introduced her ??"incredible husband" to the crowd on Saturday evening at the Invictus games, a multi-day Paralympic-style sports competition founded by Prince Harry in 2014.

“I could not love and respect him more, and I know that all of you feel the same," she said during her introduction. "Because he is your fellow veteran, having served two tours of duty in Afghanistan and 10 years of military service, he's the founder of the Invictus Games, and the father to our two little ones Archie and Lili. Please welcome my incredible husband, Prince Harry, the Duke of Sussex."

Prince Harry then made his way to the stage and gave his wife a quick kiss in front of the crowd.

This type of very public display of affection is not common among the royals — even in the most romantic of settings — making the gesture a surprising one.

Fans loved the smooch and shared their thoughts on the moment via Twitter.

"So many beautiful moments, but the kiss made me swoon," wrote one fan.

According to royal etiquette expert Myka Meier, who spoke to People about the issue in relation to Kate Middleton and Prince William, there are no explicit guidelines forbidding gestures of affection between royal spouses, but since many of their public appearances are considered work obligations as the representatives of the British Monarchy, they take a notably reserved approach when in public.

While there are plenty of rules for other aspects of life as a royal — including subtle curtseying, and to stop eating when the queen does — limited PDA is more of an unwritten rule. It is commonplace for royals to observe protocols set by the Queen, who rarely held hands with her husband in public.

Meghan Markle and Prince Harry have taken a bit more of a lax approach to some of the royal guidelines in comparison to Prince William and Kate Middleton, who remained stoic, for example, in appearance during a 2016 visit to the Taj Mahal.

“There is no actual etiquette or royal protocol that says the couple must refrain from PDA. The likely reasoning is more that while traveling on a tour such as the India trip, technically the couple are working representatives of British Monarchy,” Meier continued. “The couple are likely to show very little PDA, if any, to remain professional during their designated roles abroad," Meier told People.

But the Duke and Duchess of Sussex formally relinquished their royal duties In January 2020, which may also be a contributing factor to their increased displays of public affection in comparison to the Duchess and Duke of Cambridge.

The two have a history of pro-PDA moments, including quick pecks during a 2018 charity Polo event and a smooch during their royal tour of southern Africa in 2019.

Their heartwarming moments throughout the Invictus Games games didn't end with kisses, as Prince Harry offered an exclusive interview to two elated youth reporters for De Kindercorrespondent, based in the Netherlands, where this year's games were held.

And, during a friends and family celebration kicking off the awards on Friday, Markle touched the hearts of fans everywhere when she offered her coat to a mother to keep her newborn warm as temperatures dropped.

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