Kate Middleton was mad at her husband, Prince William, at one point.

According to Harriet Mallinson, a journalist for Express, the Duchess of Cambridge didn't like how Prince William behaved during a boys-only ski trip holiday in Verbier, Switzerland. The Duke of Cambridge joined his friends for a holiday away from home. While Middleton was left to tend to their two kids, Prince William was filmed singing and dancing in a nightclub. Prince William was also spotted putting his hand on the waist of a mystery woman. When Middleton saw the footage, she was reportedly "less than pleased."

"It was William’s choice to go away, but make no mistake Kate wears the trousers in their marriage," a source told Vanity Fair back in 2017.

"She won’t be happy with William’s antics. She thought his partying days and larking around with the boys was a thing of the past," the source added. "I imagine she’ll find this humiliating and William will have come in for a pasting."

A day after Prince William's infamous partying, Middleton joined Queen Elizabeth, Prince Charles, Prince Harry and other the senior royals in Westminster Abbey for the Commonwealth Day service. Prince William didn't make it to the event, causing the British press to call him "throne idle" for skipping the ceremony.

It has been a year since the incident happened, and the Duke and Duchess of Cambridge have already moved on from the incident. In fact, they stepped out together on Thursday for The Tusk Conservation Awards at Banqueting House in London and they looked happy.

It was the first time for Middleton to attend the event in several years. She didn't make it last year because she was still expecting Prince Louis. She was first spotted in the awards gala in September 2013, just months after giving birth to Prince George, 5.

Prince William is a patron of Tusk. Two months ago, he flew to Africa for Tusk Trust but Middleton didn't join him. According to Christina Reeves, the Duke of Cambridge "has always worked solo in his fight against illegal wildlife trade." "William's visit to Africa is in the same vein as his 2016 solo trip to Vietnam, where his goal was to urge people to stop buying rhino horn and elephant ivory," she added.

Prince William and Kate Middleton Prince William did something in the past that angered his wife, Kate Middleton. Pictured: Prince William and Middleton leave after attending the wedding of Britain's Princess Eugenie of York to Jack Brooksbank at St George's Chapel, Windsor Castle, in Windsor, on Oct. 12, 2018. Photo: Getty Images/Alastair Grant