Meghan Markle and Kate Middleton Have Become 'Closer Than Ever' (Exclusive)

The Duchesses are reportedly bonding over shared interests in their royal lives.

After their first ever joint outing without their husbands on Saturday, it's clear Kate Middleton and Meghan Markle are sharing a deep bond.

A source tells ET that the sisters-in-law "have become closer than ever" and have been bonding over their shared interest in their Royal Foundation work. Middleton supports many charities, including those focusing on children's mental health, sports and the arts, alongside Prince William and Prince Harry's other charity work.

Markle is planning to become involved in charity work as well as part of her royal duties. “Meghan is set to announce her first patronage imminently,” the source shares.

The pair's growing connection was on clear display Saturday, as Markle and Middleton cheered on Serena Williams at Wimbledon, chatting and laughing in the stands. Sadly, Williams lost to her opponent, leaving longtime fan Markle sad for her friend, the source shares.

"Meghan was misty-eyed as Serena Williams lost in straight sets to Angelique Kerber,” the source says, adding that Meghan had “really hoped Serena who had stood by her for many years would win the tournament.”

Meanwhile, after the match, Williams said she was going home to play with her daughter, Olympia, and might watch a movie with her husband, Alexis Ohanian the source tells ET.

Meanwhile, William and Harry played in a polo match at the Berkshire estate of Lord Andrew Lloyd-Webber while their wives enjoyed their Wimbledon outing, the source also notes. The brothers play annually in exclusive polo matches to raise money for charity. To date, "The Duke of Cambridge and Duke of Sussex have made more than £1 million pounds for the charities that mean the most to them," the source shares. 

For more on Williams' Wimbledon match, watch the video below: