US President Donald Trump's forthcoming July state visit to the UK has caused outrage on the streets of Britain, with mass protests taking place regarding the former reality TV star being invited to stay at Buckingham Palace.
Along with the inhospitable reception the 70-year-old is receiving from Britain – a nation which his Scottish mother, Mary Anne MacLeod Trump, called home – the quiet feeling of awkwardness for the British Royal Family is bubbling beneath the surface.
During a joint press conference with Trump at his new home last Friday, Theresa May officially invited the president to the UK on behalf of Queen Elizabeth II.
Blissfully unaware of the ruckus to follow, she said: "I have today been able to convey Her Majesty the Queen's hope that President Trump and the First Lady would pay a state visit to the United Kingdom later this year. I'm delighted he's accepted that invitation."
But as it stands, relations have the potential to be rather strained between the abrasive leader of the free world and senior royals. Here's why.
Climate change – Trump vs Prince Charles
There may be a very chilly atmosphere at the opulent state dinner between Trump and Prince Charles over global warming. Trump previously dubbed climate change a "hoax" and removed the White House website page on the subject within hours of taking office.
Charles, on the contrary, has been quite vociferous about his views on climate change, making his first speech on the environment in 1968.
Charles is on record as believing that: "Since the Industrial Revolution, human beings have been upsetting that balance [of nature], persistently choosing short-term options and to hell with the long-term repercussions."
In a recent article for the Mail on Sunday, he also wrote: "We might be more inclined to think about the longer term if we were more aware of what is happening around us. Perhaps daily weather forecasts could include a few basic facts about the Earth's vital signs, or details of where climate change is increasing the likelihood of damaging weather?"
By contrast, Trump has said on Twitter: "The concept of global warming was created by and for the Chinese in order to make US manufacturing non-competitive."
Charles may be able to change Trump's mind on the matter, as the president seemed more open to addressing the effects of climate change in an interview with the New York Times in 2016.
He told them: "I have an open mind to it. We're going to look very carefully. I have a very open mind. And I'm going to study a lot of the things that happened on it and we're going to look at it very carefully."
However, a White House source warned that the president would "erupt" if the prince attempted to lecture him on the subject.
The American tycoon also perceived Princess Diana as "the ultimate trophy wife". TV presenter Selina Scott revealed that Trump had "bombarded her at Kensington Palace with massive bouquets of flowers, each worth hundreds of pounds" – another detail that may not have gone down too well with the late Princess of Wales' ex-husband.
Queen's strong relationship with the Obamas
Queen Elizabeth II has been known for her dislike of being touched, and eschews physical contact with most people if she can help it, aside from obligatory handshakes.
But Michelle Obama was the exception to the Queen's unwritten rule, as the former first lady famously embraced the British monarch on the Obamas' first official visit to the UK in 2009. A series of relaxed and friendly encounters between the Obamas and the Queen and Prince Philip have followed since, suggesting they enjoyed an especially close bond.
Furthermore, the Obamas also worked their charms on the younger senior royals, including the Duke and Duchess of Cambridge and Prince Harry. The US couple enjoyed dinner at Kensington Palace with the trio, and even met a sleepy Prince George in his sleeping gown, proving relations were very friendly between the group.
Prince Harry fears Trump is a threat to human rights
A recent report suggests that the 32-year-old royal "is not a fan" of the US President's, with a source telling US Weekly that he believes "the president is a serious threat to human rights".
Harry is said to have "been vocal" in expressing his thoughts about the business mogul ever since he announced that he will be running for presidency, and the publication claims that he dislikes the newly-elected American president.
The prince is also now in an intense relationship with the star of Suits, the mixed-race actress Meghan Markle, and he will not look kindly on the on the perceived white nationalist patina that now glosses the Trump administration.
Finally, Trump's bragging that he could have bedded Harry's mother, Princess Diana, before dismissing her as "crazy" will have offended her devoted son and his brother, Prince William.
He's rubbed Kate Middleton up the wrong way
The Duchess of Cambridge and husband Prince William will have been offended by Trump's patronising chiding of Kate Middleton during her topless paparazzi scandal.
Trump made comments about Middleton's "nude" sunbathing after French magazine Closer published topless photos of her shot with a long lens by lurking photographers.
He tweeted: "Kate Middleton is great--but she shouldn't be sunbathing in the nude--only herself to blame.
"Who wouldn't take Kate's picture and make lots of money if she does the nude sunbathing thing. Come on Kate!" he added.
As differences of opinions have begun to emerge between Trump and members of the British Royal Family, it will be interesting to analyse the relationship and chemistry between them all if and when the US President conducts the planned state visit to the UK this summer.