While rumor mills have been saying that former sweethearts Cressida Bonas and Prince Harry are now back in each other's arms, a recent report claimed that Kate Middleton does not approve it.

According to Celeb Dirty Laundry, the 33-year-old Duchess of Cambridge might have considered the step-sister of Isabella Calthorpe as a threat.

The entertainment site noted that Calthorpe could have been the "the woman Prince William really wanted to marry."

The report further speculated that the "bad blood" among the three women actually "goes deeper than just a dislike or a love mismatch" especially that Kate Middleton "is smart enough to see Prince Harry and Cressida's relationship as a threat to her marriage, position in the royal family and power."

Celeb Dirty Laundry alleged that the mother of two even "used" Prince William to convince him not to end up in the altar with Cressida Bonas.

Furthermore, the site revealed that letting the on-again-off-again sweetheart of his brother-in-law get into the royal family may have a terrible impact to her marriage which reportedly could result to "another royal cheating scandal and divorce."

In the meantime, she was said to be pushing Prince Harry to another ex, Chelsea Davy, whom she reportedly thinks is a better choice.

Based on the report of "Life & Style" magazine (as shared by "OK!"), the younger prince and Cressida Bonas have remained friends even after they parted ways during the early part of 2014, something which Kate Middleton may not just be happy about.

An insider reportedly shared that "Kate doesn't like Cressida at all."

"It's not just that she thinks Cressida isn't a love match for Harry," the unnamed source stated. "It goes deeper than that. She doesn't want her in the family."

Since she is the step-sister of Calthorpe, the mother of Prince George and Princess Charlotte appeared to be uncomfortable about her rumored reunion with Prince Harry.

"Kate hates even hearing Isabella's name mentioned," the source reportedly disclosed about the issue between Kate Middleton and Cressida Bonas. "She was obviously upset when Cressida and Harry started dating."