Princess Diana and Prince Charles' iconic wedding day kiss on the balcony of the Buckingham Palace has been voted as Britain's most memorable smooch. However, the kiss almost didn't happen due to the Prince of Wales' "standoffish" mood at the time.

The iconic kiss sealed Princess Diana and Prince Charles' fairytale wedding in 1981. After they tied the knot at St. Paul's Cathedral in London, they straightly went to the Buckingham Palace, where they walked outside the balcony to acknowledge the crowd.

As they waved to the people outside, they started chanting for a kiss. The delighted Princess Diana was too willing to oblige, reaching across Prince Charles to kiss him. However, the heir to the throne seemed a little reluctant to kiss his wife in public.

Former royal protection officer Ken Wharfe said, on History Channel's Photos That Change the World, that Princess Diana looked genuinely happy at the time. It was evident that she was madly in love with Prince Charles.

"But the Prince of Wales was rather standoffish. Charles was hesitant, whereas Diana went straight in for the kiss," he said, via Express. The kiss was also one of the royal protocols that Princess Diana broke, but ultimately started a new tradition.

It was the first time that a royal couple kissed on the balcony of the Buckingham Palace. Now, it has become a norm for newly-wedded royals to share a kiss in front of the public. It was also voted as the most memorable kiss in Britain.

According to Daily Mail Online, a U.K. study found that Princess Diana and Prince Charles' wedding kiss is still well remembered by the nation. Commissioned by the History Channel, the research's respondents were asked to rate the kisses that they thought the most memorable in Britain.

A great number of partakers voted for Princess Diana and Prince Charles' kiss, saying it was their most memorable moment. About 600,000 people gathered on the streets of London to see the Prince and Princess of Wales' wedding day. Roughly 750 million people, on the other hand, watched their nuptial on television, per BBC.

Prince William and Kate Middleton's sweet embrace on the balcony of Buckingham Palace came as the second most memorable moment in Britain, earning 24 per cent of votes. Prince Harry and Meghan Markle's kiss on the steps of St. George's Chapel at Windsor Castle came third of the most memorable royal kiss.