Prince William and Kate Middleton
Prince William and Kate Middleton journey by carriage procession to Buckingham Palace following their marriage at Westminster Abbey on April 29, 2011 in London. Getty Images/Sean Gallup

Kate Middleton and Prince William broke the royal protocol on their wedding day with their balcony kiss.

Most royal brides and royal grooms share a royal kiss on the balcony following their royal wedding. However, the Duke and Duchess of Cambridge did something that the previous couples didn’t do.

According to Abbie Llewelyn of Express, Prince William went back for a second peck after the first kiss. Royal experts felt that it was something new and accused the couple of breaking the royal protocol by doing so.

“Everyone kind of went ‘Oh, that was it?’” Victoria Murphy said in the documentary “Prince William at Thirty.”

“So later he went back in for another one, so we got two kisses on that day.”

TV presenter Philip Schofield added that after that, they had a fit of fumbling kisses here and there.

“Beautiful kiss, worked really well. Huh! Oh, you’re going in for it again! Once again, you know, the perfect break with tradition,” he added.

The Sun’s royal photographer Arthur Edwards recalled how he managed to get his winning shot featuring the couple’s balcony kiss. He admitted that his photo was the “page one picture” and proudly said that he didn’t only capture the kiss but how their lips were coming closer and closer and then the kiss.

Aside from their balcony kiss, Prince William and Middleton also broke the royal protocol with their guest list. Initially, their original guest list included an extensive array of VIP guests including head of state and the kings and queens from around the world.

The Duke and Duchess of Cambridge reportedly approached Queen Elizabeth II and asked Her Majesty if they could do things slightly differently. The Queen advised them to rip the list up and invite anyone they want. The Queen allowed them to do things their way and encouraged them to invite their friends.

In related news, Prince William celebrated his 37th birthday on Friday. Prince Harry and Meghan Markle were slammed for not posting a decent birthday greeting to the future king. The Duke and Duchess of Sussex only commented on Kensington Palace’s post on Instagram and wrote a short message “Happy Birthday to the Duke of Cambridge” which sound very formal compared to how they greeted Queen Elizabeth II and Prince Louis.

Royal commentator Ingrid Seward felt that what Prince Harry and Markle did was a “deliberate snub” to Prince William. She added that it was “pretty rude” and would be construed as “purposeful.”