Royals Meghan Markle and Prince Harry Had a Huge Secret in This Photo from the Toronto Invictus Games Meghan even hinted at the big news with her outfit choice — yet their secret remained undetected By Stephanie Petit Stephanie Petit Stephanie Petit is a Royals Writer and Reporter at PEOPLE. People Editorial Guidelines Published on July 29, 2020 02:03 PM Share Tweet Pin Email Meghan Markle and Prince Harry were hiding something major during their first official outing together. The couple made their public debut at the Toronto Invictus Games in September 2017 after over a year of dating, holding hands and smiling as they headed to watch wheelchair tennis. But there was a secret reason for their look of love: they were already engaged, according to the new book Finding Freedom: Harry and Meghan and the Making of a Modern Royal Family. Meghan hinted at the big news in a subtle way — she wore a classic white button-down shirt dubbed the "Husband Shirt" from her designer friend Misha Nonoo's collection — yet their secret went undetected. Prince Harry Had a Secret Instagram While Dating Meghan Markle — Find Out His Music-Inspired Name Meghan Markle and Prince Harry. Splash News Online Two months later, on November 27, Clarence House announced Meghan and Prince Harry's engagement — but the couple continued to hold back on revealing the exact date of when they actually got engaged. "It happened a few weeks ago, earlier this month, here at our cottage; just a standard typical night for us," Harry said during their engagement interview. Meghan Markle and Prince Harry at the Toronto Invictus Games in 2017. Danny Lawson/PA Images/INSTARimages.com Meghan Markle and Kate Middleton Had 'Awkward Moments' in Royal Relationship, New Book Claims Meghan added that the proposal happened on a "cozy night" while they were making a dinner of roasted chicken. "It just – just an amazing surprise, it was so sweet and natural and very romantic," she said. "He got on one knee." Samir Hussein/WireImage Finding Freedom, co-authored by Omid Scobie and Carolyn Durand, explores the Duke and Duchess of Sussex's journey, starting from the early days of their fast-moving romance and culminating in their decision to step down as senior members of the royal family and move to Los Angeles with son Archie. Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! A spokesperson for Meghan, 38, and Harry, 35, previously said in a statement, "The Duke and Duchess of Sussex were not interviewed and did not contribute to Finding Freedom. This book is based on the authors’ own experiences as members of the royal press corps and their own independent reporting."