While it's hard to imagine someone as naturally elegant as the Duchess of Cambridge ever getting jealous of another woman, new reports suggest that Kate Middleton may not approve of her brother-in-law Prince Harry's newest girlfriend, and Celebuzz has the scoop on why.

Prince Harry has been dating Cressida Bonas since May 2012, and apparently the Duchess does not approve. Despite her start as a commoner, Middleton has been in royal circles for years, having met her husband even before the two started university together. Nonetheless, she still had to work her hardest to chase down the man of her dreams. During the spring of 2007, after Middleton and Prince William split for the second time, the Duchess had to fight Bonas's half-sister, Isabella Anstruther-Gough-Calthorpe, for the prince's attention, as he made a "beeline" for the actress immediately following their break-up.

"[William] had fallen for [Calthorpe] in a huge way and wanted to be with her," a source told the Daily Mail. "He propositioned her several times that summer and although Isabella was single, she knocked William back and said it would be too damaging for her and her career. Kate was very aware of his obsession with Isabella and she was incredibly threatened by her. Isabella is drop-dead beautiful and would leave any girl in the shade. I would go so far as to say that William dumped Kate because he thought he had a chance with Isabella and Kate knew that. Kate accepted William back again but on the condition that he would not speak to Isabella again."

So it turns out that if things had gone differently, Calthorpe may have been the Duchess of Cambridge today!

Things all evened out, however, as Calthorpe married her longtime boyfriend, Sam Branson, this March in South Africa, and was invited to the royal wedding in 2011. However, the Telegraph reports that Calthorpe was not a guest at the breakfast reception nor the Buckingham Palace celebration that evening, and it did not sit well with her sister.

"Cressida has said Kate is not keen on her relationship with Harry," a source told the Telegraph. "Cressie and Isabella could not be closer. Where she goes, Bella goes. Kate does not like Isabella because William loved her, and that caused their break-up. Bella's treatment at the royal wedding won't be forgotten."

If the reports are true, it should prove to be quite an interesting spin on royal life if Prince Harry ever proposes to Bonas!