Prince Harry's whisper to wife Meghan Markle whilst on stage at the Royal Foundation Forum has been highlighted in a bombshell biography.
Royal brothers Prince William and Prince Harry along with their partners the Duchess of Cambridge and Meghan Markle - dubbed the 'Fab Four' at the time - were on stage at the 2018 event promoting their work initiated by The Royal Foundation.
It was Meghan's first official engagement with her future in-laws - but author Tom Bower claims the former American actress's words upset the foundation's executives and created an awkward atmosphere among the four.
In an extract from ‘Revenge: Meghan, Harry and the War between the Windsors', published today by Blink Publishing, Bower claims that the Duke of Sussex's interjection during Meghan's speech was much more sinister than first thought.
While the four all laughed at Prince Harry's comment, the author paints a picture that it was his way of reminding his fiancé at the time to not get ahead of herself.
Harry raised the fact they still had a wedding to plan when Meghan was outlining the important work she hoped to get involved with in empowering women.
"With so many campaigns like MeToo and TimesUp, there’s no better time to continue to shine a light on women feeling empowered and people supporting them," she told the audience.
"You’ll often hear people say, 'Well you’re helping people find their voice' and I fundamentally disagree with that, because women don’t need to find a voice. They have a voice, they need to feel empowered to use it, and people need to be encouraged to listen."
Bower argues that while the royals are patrons of the Foundation, they have limited influence on its direct activities.
"That power was exercised by the Foundation’s executives, an unimpressive group criticised for ineptly moving the royals around like chess pieces," Bower wrote.
"While William, Kate and Harry had become accustomed to their motley behaviour, Meghan’s arrival as a natural recruit for the Foundation’s philanthropic work disturbed the rhythm of the executives’ habits.
"Her feminism also upset their ingrained conservatism."
He continued to claim that Meghan ignored the "royals’ role impartially to foster national unity".
"She had not been invited to join the Royal Foundation to reinvent the Royal Family’s customs," Bower wrote.
"While Meghan spoke, Harry spotted William’s rictus grin... "‘Wedding first,’ Harry whispered loudly.
"‘We can multi-task,’ Meghan replied to the unexpected interruption."
Bower continued: "Instead of speaking about mental health she had been swept up by her vision of a modern monarchy. She imagined herself as centre-stage rather than recognising the reality of standing on the periphery. As the discomfort among the four became obvious, William tried to restore harmony.
"The Crown, he volunteered, should be ‘relevant to their generation’ but the Four should ‘not reinvent the wheel’."
Bower also made reference to disagreements between the Fab Four after they were probed by members of the public in the audience.
He wrote: "Disputes, they acknowledged, existed. ‘They come so thick and fast,’ said Harry. ‘Working as a family does have its challenges.’ We don’t know,’ William admitted when asked whether their disagreements had been resolved."
'Revenge: Meghan, Harry and the War between the Windsors' is set to rock the Royal Family as it examines the rift between the Sussexes and the royals.
It includes allegations that the Duchess threw a cup of tea in the air during a Royal tour, while the Queen was said to be pleased she couldn't attend Prince Philip's funeral.
