A Drinking Game Forced Princess Kate and Prince William to Confirm Their Romantic Relationship, Source Says

Like most celebrities or members of a monarchy thrown under an endless spotlight, Prince William and Princess Kate tried to keep the beginning of their romantic relationship under wraps.

They were somewhat successful, royal biographer Robert Jobson writes in his new book, Catherine, the Princess of Wales, until the pair attended a dinner party with friends where those in attendance decided to partake in the popular drinking game, "Never Have I Ever."

According to Jobson, Carly Massy-Birth, one of the Prince of Wales' ex-girlfriends, was also present, and during the confessional-like game revealed Prince William and Kate Middleton were dating.

"Perhaps unwittingly, Carly exposed William’s secret love affair with Catherine, much to the prince’s chagrin," Jobson writes in his biography, as reported by People.

In 2002, royal biographer Katie Nicholl made the same claim in her book The Making of a Royal Romance.

"She 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," a source who attended the party told the author, before adding that that every single one of the party guests were "in shock."

The same source alleged that in response, Prince William shot his ex-girlfriend a "thunderous look" before whispering under his breath: "I can't believe you just said that."

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

While the public revelation was a shock, it wasn't what anyone at the time could consider "breaking news."

"Among the student community, it was an open secret that they were a couple," Jacobson writes, adding that the Prince and Princess of Wales frequently spent time together, be it walking to class, going grocery shopping or listening to music in the evenings.

The pair first met in 2001 while studying at St. Andrews University in Scotland. According to prevailing rumors, William "won Middleton over" after paying £200 for a front row seat to watch his future bride walk down the runway during a student fashion show for charity.

According to The Crown historian Robert Lacey, their initial meeting and subsequent courtship was no accident—Middleton was allegedly "strategic" when it came to her relationship with the future King.

“Kate was very strategic,” Lacey said, as reported by Elle. “She gave up her place at one of Britain’s premier universities, Edinburgh, and opted for another one that probably didn’t have the same academic standard.

"She had already been to Edinburgh to get her flat accommodations sorted out but switched universities and switched her courses to history of art because that was William’s," he continued. "She delayed her own education by a year and even takes the chance she won’t get into St. Andrews.”

Whether by chance or calculated choice, things have apparently worked out for the couple, who recently celebrated their 13th wedding anniversary.