“Kate Middleton Relaxes at a Surprise Hen Party: Shows Off Like Cheryl Cole!”

Clad in a figure-hugging bodysuit, Kate even perfected the dance routine to Cole’s 2009 hit “Fight for This Love,” royal biographer Robert Jobson writes in his new biography of the Princess of Wales

Kate Middleton attends the Day-Glo Midnight Roller Disco on Sept. 17, 2008. Photo: Max Mumby/Indigo/Getty

Ahead of her April 29, 2011 wedding to Prince William, Kate Middleton “let her hair down” at her bachelorette party.

In his new book Catherine, the Princess of Wales, royal biographer Robert Jobson writes that Kate’s sister and maid of honor, Pippa Middleton, organized a night to celebrate at a mutual friend’s house with a “minimal guest list.” Kate’s college roommate from the University of St. Andrews Olivia Beasdale made the cut, as did two of her friends from her time at Marlborough College, Alicia Fox-Pitt and Rose Astor.

While “dressed up in a figure-hugging bodysuit,” Kate carried out “an exaggerated impersonation” of pop star Cheryl Cole, performing the singer’s 2009 hit “Fight for This Love.” It’s a fact that Prince William confirmed himself at Queen Elizabeth’s Diamond Jubilee concert in 2012, when William met Cole and told her, “Did you know you’ve got a bit of competition?”

Liam Payne and Cheryl Cole attend the Fayre of St James’s on Nov. 29, 2016.Dave Benett/Getty

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Prince William wasn’t the only person close to Kate to tell Cole all about it: “She [Kate] even learnt the dance routine and was step-perfect by all accounts, as her sister Pippa and brother James also came over and told me all about it,” Cole said, according to Jobson’s book, out Aug. 6.

Cole eventually met Kate herself, and of the encounter, Cole told Closer (per Jobson’s book), “We had this amazing moment. She’s so ordinary! I mean, obviously she isn’t because she’s a princess, but she’s easy to get along with.”

As for Prince William’s bachelor party? His stag night was a “low-key event” with about 20 friends, Jobson writes. The group “went clay pigeon shooting before going surfing during a weekend at a Devon mansion named Harland Abbey.”

Prince William and Kate Middleton.Indigo/Getty

The Princess of Wales’ upbringing outside of the royal fold is part of what endears her to so many, Jobson recently told PEOPLE.

“She is somebody in the royal family who understands what it’s like not to be a member of the royal family. Her children have been born princes and a princess and her husband was born a prince and her father-in-law was born to be king,” he said. “She is the one person who can connect with the people in a way that no other princess in the past has ever been able to do.”