Kate Middleton dresses
Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge pass British Prime Minister Theresa May as they attend the Men's Singles final on day thirteen of the Wimbledon Lawn Tennis Championships at All England Lawn Tennis and Croquet Club on July 15, 2018, in London, England.Getty Images

Kate Middleton was not always surrounded by guards. At one point, she was a commoner too, doing summer jobs. It was during this time that a prank was played on the Duchess of Cambridge that had left her mortified.

Cal Tomlinson, one of Kate's colleagues during her summertime at Ocean Village Marina in Southampton, recalls the prank in the book Kate: The Future Queen, written by the royal expert and biographer Katie Nicholl.

Kate Middleton's duties in the marina involved cleaning the decks, greeting guests and giving them safety demonstrations. It was during one of these demonstrations, Kate was completely caught by surprise as a staff had rigged her life vest with condoms. As she inflated the vest, the condoms were everywhere around her leaving her to feel "very embarrassed" in front of stunned guests.

Kate Middleton
Kate Middleton, Duchess of CambridgeGetty Images

"When she pulled the toggle, the thing inflated and a load of condoms fell out," Cal recalls how the incident happened. "She was mortified and very embarrassed," he further added. That the incident had left a deep impact on the Duchess's life, remembered Cal. "She was angry at first, but she settled down, and I don't remember her ever getting them back," he pointed out how the Duchess responded. Following that summer Kate went onto attend college.

In the University of St Andrews, she met Prince William and it was in Fife, Scotland in 2001 did she make a pact with the Prince of secretly marrying each other.

Though Express has found out that Nicholl later contended in her 2011 book, The Royal Romance, did Prince William and Kate Middleton makes a secret pact of marrying each other after their second major break up.

"I suppose what none of us knew was that she and William had actually made a secret pact to be married way back in 2007, after they got together after their second major break-up. And we know that this is a couple who are very good at keeping secrets. So really, Kate had the last laugh, because she's got her prince," Nicholl contended in the book.