Kate Middleton and Prince William
Prince William and Kate Middleton attend the 1st Battalion Irish Guards St Patrick's Day Parade at Cavalry Barracks on March 17, 2019 in Hounslow, England. Getty Images/Gareth Fuller

Kate Middleton looked happy even when Prince William escorted his ex-girlfriend to a wedding the three of them attended.

The Duke and Duchess of Cambridge had an on-again, off-again relationship during their decade-long courtship. Prior to meeting each other, they were romantically involved with other individuals, too.

Middleton dated Willem Marx when she was at Marlborough College. According to reports, he was the duchess’ “first love.“ On the other hand, Prince William also had his share of partners before Middleton and one of them was Jecca Craig whom he met while taking a gap year in Kenya.

According to Sunday Express’ 2005 report, Prince William and Middleton were invited at his best friend Hugh van Cutsem’s wedding to Rose Astor. The Duke of Cambridge served as an usher at the wedding and escorted both Middleton and Craig to their seats, but there was no apparent tension between the two women.

“If there was any tension, between the two women they did not show it,” one source said.

One guest added that Middleton looked great during the event. The Duchess of Cambridge was reportedly in good spirits.

“Kate looked as pleased as punch as she arrived at the church,” the insider said.

“She was smiling enigmatically as though she had a secret. She looked really happy.”

Aside from Craig, the Duke of Cambridge was involved in a number of other women. Prior to meeting Middleton at St. Andrews University, Prince William had a crush on Camilla Parker Bowles’ niece Emma Parker Bowles. He was only 17 at the time while she was 25.

Prince William looked lovingly at Emma while she was “hanging on his every word.” The duke “gazes at her so adoringly that it becomes a bit embarrassing.” Prince William was a picture of a young man in love. However, their romance soon fizzled out.

Prince William was also linked to Alexandra Knatchbull, Carly Massy-Birch and Isabella Anstruther-Gough-Calthorpe. The father of three reportedly made amorous advances to Isabella and she’s the only woman who could make Middleton “green with envy.”

Prior to marrying Middleton, Queen Elizabeth II warned Prince William to be very careful when choosing a wife because Her Majesty didn’t want another royal divorce. The Queen’s reminder convinced Prince William and Prince Harry that once they get married, it would be for keeps.