Kate Middleton issued Prince William an ultimatum after 'unacceptable' behavior

While Prince William and Princess Kate appear to have a flawless relationship these days , it wasn't always smooth sailing for the royal couple.

Their love story began at the University of St. Andrews in Scotland . Throughout their twenties, they had an on-again, off-again relationship before tying the knot in a grand wedding ceremony at Westminster Abbey in 2011.

One of their breakups was reportedly due to an ultimatum from an irate Kate after the Prince of Wales' unacceptable behavior left her feeling utterly "humiliated" and treated like a "doormat". A 2007 report during one of their separations claimed that Kate issued the ultimatum after William was caught twice in quick succession getting cozy with other women in nightclubs.

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According to royal expert Katie Nicholl, this was the first time Kate had ever given such a warning, as she was completely "humiliated" by photos of William partying, after years of brushing off advances from other women towards her boyfriend.

Nicholl quoted a friend of Kate's, who preferred to remain anonymous, saying: "She has coped for years with girls flinging themselves at her boyfriend and for a while she found it humorous and even flattering. But after his recent behavior she gave him an ultimatum and told him that every time he behaved like that in public he was cheapening her image as well as his own."

She continued: "She told him she wasn't prepared to be treated like a doormat and that his carefree behaviour was affecting her image. She gave him quite a pasting.

"In the past she had always let go of things like that, but this really bothered her." The first incident reportedly took place at London nightclub Boujis, previously a favorite spot for William, where he was seen in a "drunken embrace with a pretty blonde".

Not long after, photographs surfaced showing William dancing with another woman during a night out in Bournemouth, causing a stir in the press.

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