Prince William revealed Kate romance during classic British drinking game

Prince William’s relationship with Kate Middleton was initially ‘shouded in secrecy’

Prince William’s ex-girlfriend “unwittingly” revealed his relationship with Kate Middleton during a fateful game of Never Have I Ever with friends, a new biography has revealed.

The now heir to the throne, 42, met his future wife while studying at St Andrew’s University in Scotland and the pair started out as friends.

However, over time, romance blossomed and it was initially “shrouded in secrecy” because of William’s position within the royal family.

But the cat was let out of the bag when William’s former flame, Carly Massy-Birch participated in a game of “Never Have I Ever”.

Popular with students, it involves participants questioning the group to discover if they have done something, and if they have, they typically take a drink.

Royal author Rob Jobson explained that the “revealing moment occurred during a dinner party with friends attended by Carly Massy-Birch” who was one of the prince’s ex-girlfriends.

“Perhaps unwittingly, Carly exposed William’s secret love affair with Catherine, much to the prince’s chagrin,” Jobson wrote.

When it was Massy-Birch’s turn, “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 party guest revealed in a separate report.

The guest added that everyone was “in shock” by Massy-Birch’s move and that Prince William “shot a thunderous look” at her and 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 said

Massy-Birch dated William for less than two months shortly after he arrived at St Andrew’s.

Prince William’s ex ‘unwittingly’ revealed his relationship with Kate Middleton. (Getty Images)

But this was far from the only interesting revelation made in Jobson’s new biography of the Princess of Wales.

Jobson also recounted how William called time with his initial romance with Kate, now 42, over the phone, believing that he was too young to settle down.

Jobson wrote of the April 2007 split when William was 25: “[He] told her they both needed ‘a bit of space’ to ‘find our own way’, and he was unable to promise her marriage.

“In an emotionally charged 30-minute conversation, they both acknowledged they were on ‘different pages’. It was a devastating blow to Catherine, who felt doubly let down at being dumped over the phone.

“William, of course, simply got drunk at Mahiki and started yelling about being ‘free’.”

However, it was not long before William won his long-term girlfriend back – and this was reportedly the result of Kate’s decision to let her hair down too.

“On Catherine’s return, she decided she wasn’t going to sit around moping; what was good for the goose was good for the gander,” Jobson explained.

“She turned to old friends for support, going on holiday with a girlfriend to Ibiza. They partied long into the night.”

William and Kate were married in 2011. (AP)

The former couple’s paths then crossed again in June of 2007 at a mutual friend’s fancy dress party, where Kate impressed William in a nurse’s outfit.

“[Kate] arrived dressed as a nurse and William had made a beeline for her,” Jobson explained.

“They then spent the first part of the evening deep in conversation before hitting the dance floor, where they ended up kissing.”

Upon their reunion, William informally promised to marry Kate and finally proposed during a trip to Kenya in 2010.