Prince William and Kate Middleton shared a rare moment of PDA at Princess Eugenie's wedding and fans couldn't be happier

• During Princess Eugenie and Jack Brooksbank's wedding on Friday, Kate Middleton placed her hand on Prince William's thigh, and the duke rested his hand on top of hers.
• There's no official protocol that forbids royal couples from holding hands in public.
• But there is a royal precedent, set by Queen Elizabeth II, that discourages PDA, especially during official engagements.
• While Prince Harry and Meghan Markle frequently engage in PDA, William and Middleton rarely do the same.
• William, who is second in line for the throne, may be held to stricter standards than royals who will likely never become the monarch.

During Princess Eugenie and Jack Brooksbank's wedding, Prince William and Kate Middleton melted people's hearts with a brief public display of affection.

Friday morning, eagle-eyed royal fans spotted the Duke and Duchess of Cambridge sharing a tender moment while sitting in St. George's Chapel at Windsor Castle. At one point of the nuptials ceremony, Middleton placed her hand on her husband's thigh, at which point the duke then rested his hand on top of hers — as seen in the post below by the fan account Kate Middleton Style.

On Twitter, people could not get enough of the sweet gesture.

As royal etiquette expert Myka Meier previously told INSIDER, there's no official protocol that forbids royal couples from holding hands or showing affection in public. According to Meier, the founder of Beaumont Etiquette, it all comes down to each couple's "personal preference."

"It's entirely up to each couple to do what they feel most comfortable," Meier said.

However, since Queen Elizabeth II is rarely affectionate with Prince Philip in public, the monarch seems to have set "an unwritten precedent" that discourages PDA — especially during official royal engagements, as body language expert Robin Kermode previously told the Daily Mail.

"It is rare to see royal couples holding hands on official outings," Meier told People. "A more serious engagement would warrant a more serious level of professionalism, which each royal is sure to follow."

That may be one reason why Prince William and Kate Middleton are rarely seen holding hands or engaging in PDA.

Not to mention, the Duke and Duchess of Cambridge, who married in 2011, have been working royals for a while.

As INSIDER's Kristin Salaky previously noted, William is second in line for the throne, behind only his father, Prince Charles. As such, the duke may be held to stricter standards in his role as a royal.

In comparison, Prince Harry — who is sixth in line for the throne and therefore much less likely to become the British monarch in his lifetime — frequently holds hands with his wife, Meghan Markle, in public.

Read more: Why Prince William and Kate Middleton never hold hands but Prince Harry and Meghan Markle do

Since the two married in May, the Duke and Duchess of Sussex have made headlines time and time again for their sweet public displays of affection.

Of course, it's just as likely that Prince William and Middleton simply prefer not to hold hands in public or to save such displays of affection for special occasions.

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