Meghan Markle once snapped on Prince Harry's brother during an argument about her treatment of Kate Middleton.

Royal family
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According to an explosive new book, 'Catherine, the Princess of Wales' by royal author Rob Jobson, Meghan once told Prince William to "get your finger out of my face."

Their verbal spat began after Harry and Meghan returned from their honeymoon when Kate Middleton, 42, reportedly confronted the 'Suits' actress for saying she had "baby brain," according to 'The Independent.' Meghan, 42 allegedly made the "baby brain" comment after Kate forgot a detail about her wedding. She was pregnant with Prince Louis at the time.

"Catherine, according to Harry's memoir Spare, confronted Meghan about the 'baby brain' comment and said, 'You talked about my hormones. We are not close enough for you to talk about my hormones.' Meghan was surprised, according to Harry, and said it was the way she spoke to her girlfriends," Jobson claimed in the book.

Jobson continued: "William stepped in and apparently pointed at Meghan and called her 'rude'. Meghan stood up to him and said, 'Take your finger out of my face.' "

Royal family
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According to the report, Prince William, 42, begged his younger brother to "cool the relationship" so Meghan could adjust to life as a royal family member. The book also alleged Meghan's relationship with Prince William and his wife started rocky because she reportedly "ignored the royal hierarchy."

Jobson, ABC News' royal contributor, wrote how Meghan "had not so much stepped on royal toes as stamped on them."

"When Meghan, who had forgotten her lip gloss, asked to borrow Catherine's, the duchess was 'taken aback' but reluctantly handed it to her," he added. "According to Harry, she 'grimaced' after Meghan had squeezed some onto her finger and applied it to her lips."

William and Meghan
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"Catherine, The Princess of Wales" will be available for purchase on August 6.

Tags
Meghan Markle, Prince William, Prince Harry, Kate Middleton, Royal family