Watching President Donald Trump interact with the royal family during his three day visit to the UK this week has been a little bit like watching a kettle simmer.

WHEN IS THE QUEEN GOING TO BOIL OVER, PLEASE?

Just look at this comparison of the Queen meeting Donald Trump, versus the Queen meeting his predecessor, Barack Obama. Alongside Trump, it’s clear to see that one is most definitely not amused.

The Queen is not...amused. Image: Getty.

And here?

Still not amused. Image: Getty.

You see, over the years Trump has said some pretty awful things about the royal family. Which makes things like staying with them for three days rather awkward.

Let's take a stroll down memory lane shall we.

"Come on Kate!"

In September 2012, the French celebrity magazine, Closer, published photos of the Duchess of Cambridge sunbathing topless at a secluded villa in Provence with Prince William.

The royal couple sued, and a French court ruled that the paparazzi shots were a breach of privacy. The publication was ordered to pay around $AUD161,000 in damages.

We're not sure why Donald Trump felt the need to weigh in...

Kate Middleton is great--but she shouldn't be sunbathing in the nude--only herself to blame.

— Donald J. Trump (@realDonaldTrump) September 17, 2012

And it gets worse:

Who wouldn't take Kate's picture and make lots of money if she does the nude sunbathing thing. Come on Kate!

— Donald J. Trump (@realDonaldTrump) September 17, 2012

Donald...back away from the Twitter. Nobody asked you.

William and Kate managed to avoid being in a photo with Trump during his UK visit, something that many have noted could have been a deliberate attempt to restrict the president's ability to harness the popularity of the younger royals.

He also didn't manage to get any publicity shots with Harry and Meghan.

“There's something about Lady Di. She’s hot.”

In 1993, Trump admitted in an interview with Howard Sternthat he'd most certainly be keen to date Princess Diana.

She'd just announced her separation from Prince Charles at the time, and Trump announced that he'd go there in "10 seconds."

“There's something about Lady Di. She’s hot,” he added.

But it wasn't just words. Trump proceeded to aggressively court Diana to the point where she reportedly told TV journalist Selina Scott over dinner:"he gives me the creeps."

He sent her huge bouquets of flowers and according to Scott, the late Princess was getting the feeling that she was being stalked.

Soon after her separation from Prince Charles, Trump began to aggressively pursue Diana. Image: Getty.

In 1997, not even two months after her death, Trump decided it would be appropriate to brag about the fact that he could have slept with her appearing once again on theHoward Sternshow.

“You could’ve gotten her, right? You could’ve nailed her,” Stern asked.

“Of course,” Trump replied.

In his 1997 book,The Art of the Comeback, Trump wrote: “I only have one regret in the women department – that I never had the opportunity to court Lady Diana Spencer."

In 2000, once again on Stern, he did it...again.

“I tell you what, I think she’s magnificent. Lady Di was truly a woman with great beauty. I’ve seen her a couple of times,” he said.

“You would have slept with her?” Stern asked.

“Without even hesitation,” Trump said.

“She was really beautiful, and people didn’t realise that beautiful. She was supermodel beautiful,” he said. “She had the height, she had the beauty, she had the skin, the whole thing.”

Here's some of Trump's 1993 interview. Post continues after video.

Meghan is "nasty".

In 2016, Meghan Markle appeared on The Nightly Showwith Larry Wilmore and called the future president a misogynist.

She told Wilmore she'd be moving to Canada quick-smart if Trump won the election. Funnily enough, she did move away... to London.

Trump did not enjoy the formerSuitsactress' comments, and retaliated, calling the future Duchess of Sussex "nasty" during an interview with The Sun.

Fast forward to present day, and thankfully Meghan didn't have to fake smile through a meeting with the American leader due to her maternity leave.

But, of course, that didn't stop the President from trying to smooth over the gaffe from a few years prior.

In an interview with Piers Morgan onGood Morning Britainhe claimed to have never called the Duchess of Sussex such a word.

It was all the 'fake news media's' fault.

....even though it was caught byThe Sunon audio.

If only the royal family weren't so goddamn polite.

We'd love to hear what they're saying behind closed doors.