Prince Harry and Duchess Meghan's wedding was probably the biggest feel-good event of the year, but even royals are prone to meltdowns and chaos in the lead up to their big day.
According to royal biographer Robert Jobson, whose book Charles At Seventy: Thoughts, Hopes And Dreams, shares juicy insight into the British royals, an insider revealed that Harry was "petulant and short-tempered" with members of staff in the lead up to his wedding.
The flame-haired prince, who has been known to wear his heart on his sleeve, would even raise his voice and say, 'What Meghan wants, she gets."
Planning a wedding is stressful enough, but both Harry and Meghan were so on edge that they reportedly booked a series of appointments with Ross Barr, known as 'the acupuncturist to the stars'.
Which is fair enough after Meghan's father, Thomas Markle, first staged paparazzi photos and then dropped out of the wedding. In the end, Prince Charles escorted his daughter-in-law down the second half of the aisle and everything else seemed to go pretty smoothly.
But the royal biography has indicated that both of Charles' sons can be quite unpredictable with their moods, something that he as a parent has struggled with.
"In that aspect of their nature, both princes are very much like their mother," one close source confirmed.
"They both have quite extreme mood swings, just as Diana did. She could be your best friend one minute and the next your worst enemy," another former courtier also said.
WATCH: Prince William and Prince Harry on living together.
He may be a father-of-three in his thirties, but that sibling rivalry is still there with Prince William.
Many members of staff, even operators on the Palace switchboard, say that the second in line to the throne can be "difficult" or "a little grand."
In Jobson's biography, he revealed that while the Duke of Cambridge acts like it's not a big deal, he is very competitive with his family members when it comes to media coverage.
For example, in January when a newly engaged Harry and Meghan visited Cardiff, William (who was also on a royal engagement) debuted his shocking buzzcut to the world. Perhaps he was taking a leaf out of his wife's book who always changes her hairstyle before a pregnancy is announced?
In the same biography, Jobson wrote of how Prince Charles desperately wanted to call off his wedding to Princess Diana.
Though he said it "would be cataclysmic," the Prince of Wales who was 32 at the time realised that he and the young Diana were totally incompatible.
Charles was reduced to tears and reportedly told friends, "I desperately wanted to get out of the wedding in 1981, when during the engagement I discovered just how awful the prospects were, having had no chance whatsoever to get to know Diana beforehand."