Renowned for her stiff upper lip and passion for adhering to the royal rulebook, the Queen is positively allergic to flashy shows of wealth and distasteful exhibitions of privilege - terms which perfectly describe the lavish baby shower enjoyed by Meghan Markle and her A-lister pals in New York in mid-February.
In a new interview with the UK Morning Show, royal biographer and Princess Diana's close confidant Andrew Morton revealed the monarch would have described the extravagant celebrations as "elaborate and over the top" - leading viewers to assume that Her Majesty is certainly not amused.
Speaking about the controversial five-day festivities, Morton noted "baby showers are more of an American tradition than they are British - far more Hollywood than Holyroodhouse."
"It was really something that if the Queen even knew about it, quite frankly, she would have thought it was a little bit OTT," he added.
A flurry of reports have also claimed the newly-minted Duchess has committed a cardinal sin in the eyes of HRH by making the ill considered excursion.
The opulent affair was held on February 20 at the ultra-exclusive Mark Hotel on Manhattan's Upper East Side, with Meghan's celebrity friends partying in her honour at the "most expensive hotel suite in the United States".
The Penthouse at the Mark costs a staggering $105,000 AUD per night.
WATCH: Pregnant Meghan Markle Steps Out with Serena Williams for Night on the Town After her Baby Shower
Meghan, 37, flew round trip on George and Amal Clooney's private jet and spent time with a star-studded line of up celebrities including Serena Williams, Abigail Spencer, Jessica Mulroney and Amal herself.
The Duchess' NYC holiday also involved afternoon tea at upscale French cafe Laduree, dinner at Ralph Lauren's exclusive Polo Bar eatery, a private meal prepared by multiple Michelin-starred chef Jean Georges and large swathes of pink roses - totalling a reported cost of more than $600,000 AUD.
Writing for the Sun UK, Princess Diana's former butler Paul Burrell also weighed in on the debate by slamming the shower as "over indulgent", adding Meghan must quickly learn the difference between royalty and celebrity.
Burrell further claimed Prince William and Kate Middleton would be disgusted about the obscene cost and distasteful display of affluence.