One is not amused: Donald Trump's embarrassing royal family blunder

Prince Charles, Prince of Wales and Camilla, Duchess of Cornwall meet US President Donald Trump and wife Melania at Clarence House. Photo / Getty

It is a startlingly awkward photo. Four of the world's most famous people standing stiffly in an overstuffed room, rictus grins firmly in place.

On Tuesday, Prince Charles and Camilla, Duchess of Cornwall played host to Donald Trump and his wife Melania, inviting the couple to their London residence, Clarence House.

Looking at the image it's impossible not to wonder what they might have talked about given Mr Trump has never shown an interest in Tuscan architecture, Charles in scoffing KFC, Camilla in Valentino's latest collection or Melania in riding to the hounds.

Suffice to say, none of them look like they are having a particularly good time.

But like it or not, this is the stuff that presidents and future kings must suffer through — diplomatically-deigned tete-a-tetes with a nice side of cake. All of which should have added up to nothing more notable than a briefing footnote or a curt mention in the Court Circular.

Instead, as per the bumbling president's other forays to Old Blighty, this rendezvous was marred by the sort of protocol-busting antics that for any lesser mortal would have seen them bumped off the Cornwalls' Christmas card list, reports news.com.au.

See, when you are a member of the royal family, there are various minor daily indignities you never have to suffer such as taking the bins out or queuing. Being kept waiting is another one. When you have an HRH stuck on the front of your name, it is your prerogative to abuse other people's schedules and to force them to dillydally.

However, this week Mr Trump gave the future king a healthy taste of what it's like to be left staring at the clock and killing time.

According to various reports, POTUS and FLOTUS kept the Prince and Camilla waiting for nearly an hour. The foursome had been scheduled to enjoy afternoon tea (just imagine the calibre of finger sandwich!) but the embattled politician arrived 54 minutes later than the appointed time.

Vanity Fair reports that when the Trumps did roll up, they spent about 15 minutes with the Prince and the Duchess, which is probably barely enough time to scoff a scone or two and make polite conversation royals' seeming penchant for ceramic animals.

Sure, London's heaving traffic was to blame but this is not the first time Mr Trump has flouted the royal rules.

While the Queen might have met 11 out of the last 12 presidents of the United States, Mr Trump is the only one who is known to have turned up late to meet Her Majesty.

When he visited the UK in 2018, he and Melania kept the monarch twiddling her thumbs, metaphorically speaking, when they travelled to Windsor Castle to meet her.

Donald Trump walks in front of the Queen at Windsor Castle. Photo / Getty

There was another snafu to come that afternoon. It is customary for the now 93-year-old to walk ahead of other people, however Mr Trump either wasn't told or had decided to ignore custom. When the pair went to inspect the guard, a seemingly oblivious Mr Trump moved ahead of the Queen then stopped, forcing her to manoeuvre around him.

Then there was the President and First Lady's trip to London in June this year as part of the D-Day anniversary commemoration which made a lasting impression — for all the wrong reasons.

During that particular trip, the President's official helicopter Marine One landed twice in one day on the vast, showstopping lawn at Buckingham Palace, along with Nighthawk, a support helicopter. Unfortunately, Her Majesty's beloved grass bore the brunt of all this military might with the wheels leaving divots and the engines causing burn marks.

One was most definitely not amused.

The Queen revealed her displeasure when Australian Prime Minister Scott Morrison rolled up for a royal audience the following day.

A source close to the PM said at the time: "He had got off the plane and went straight to the palace to see the Queen, who led him out to the gardens and said: 'Come and look at my lawn. It's ruined.'"

Get off my lawn. Photo / Getty

Ravaged grass. Sandwiches left to dry out as the clock ticks irrevocably onwards (I'm guessing). A future king left to twiddle his signet ring. You know what all of this adds up to? Donald and Melania have just accidentally provided the perfect ingredients for a tense, drama-filled future episode of The Crown, and most likely they haven't finished yet.

Daniela Elser is a royal expert and writer with 15 years' experience working for a number of Australia's leading media titles.