Prince William furious after leak of top secret about Kate Middleton

Prince William reportedly became angry after a top secret involving Kate Middleton leaked, according to a report.

Future King William could not control his anger and gave a thunderous response when his romance with future wife Kate Middleton was outed at a university dinner party.

According to royal author Robert Jobson's new book, Catherine, the Princess of Wales, "it was an open secret, among the student community, that Kate and William were a couple". But it was one of William's ex-girlfriends who officially outed their relationship. 

William's ex Carly Massy-Birch "perhaps unwittingly" exposed the couple during a boozy game of 'Never Have I Ever' with other friends, "much to the prince's chagrin," Jobson claims.

The biographer also cited the work of Katie Nicholl, who also penne about the big night in her 2013 book "Kate: The Future Queen."

A guest at the party told Nicholl: "[Carly] announced, 'I've never dated two people in this room', knowing full well that William was the only one who had because Kate was sitting next to him."

According to that guest, everyone at the dinner was "in shock". Prince William, they added, "shot a thunderous look" at his ex and reportedly whispered under his breath, "I can't believe you just said that."

"We knew they were together, but it was the first time William confirmed his and Kate's relationship in public," the source added.

Despite his initial frustration, William was able to move past the incident and the couple remained friends with Carly. She was lucky enough to be invited to their wedding in Westminster Abbey in 2011.