"When he felt he might lose her, he worked hard to get her back," a source tells PEOPLE
Sean Penn
Sean Penn and Leila George in March 2020
| Credit: Getty

Sean Penn put in work to win back Leila George prior to their nuptials last week.

The Oscar winner, who turns 60 later this month, tied the knot with George, 28, on July 30, during an intimate ceremony with only a few loved ones present. Though the pair have been romantically linked since 2016, a friend of George's tells PEOPLE that the pair reunited early this year after a stretch of being on and off.

"Leila has been in Sean’s life for a while. They got together and then they broke up, and Sean won her back," says the source. "He realized he had made a mistake and when he felt he might lose her, he worked hard to get her back."

Penn split from Charlize Theron in June 2015. He was previously married to Robin Wright from 1996 to 2010, and Madonna from 1985 to 1989.

The source adds that the time self-isolating together during the novel coronavirus (COVID-19) pandemic helped strengthen their connection. Penn and George even embarked on humanitarian efforts with each other throughout the public health crisis, including helping set up testing sites in Los Angeles.

"They got back together during COVID and became really close and got engaged a few months ago, early during quarantine," explains the source.

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Penn confirmed his new marriage during an appearance on Late Night with Seth Meyers, explaining that their officiant patched into the ceremony via Zoom.

"It was Thursday," Penn told Seth Meyers after showing off his ring. "We did a COVID wedding. By that I mean it was a county commissioner on Zoom and we were at the house, my two children and her brother. And we did it that way."

Penn shares two kids — daughter Dylan Frances, 29, and son Hopper Jack, 26 — with ex-wife Wright.

George is the eldest child of actor Vincent D'Onofrio and Italian actress Greta Scacchi. Though she's the former couple's only child, she also has three brothers: Matteo, 22, from her mom's side and Elias, 20, and Luka, 12, from her dad's side.

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Meyers went on to point out that such a small-scale wedding sounds less stressful than his own large wedding back in 2013, to which Penn jokingly agreed. "Let’s say there are socially liberating factors under COVID," he quipped.

In March, Penn and George made a rare appearance together while attending a fundraiser the actress produced for wildlife relief in Australia following the devastating bushfires.

“It’s the most important thing [to have his support]. I wouldn’t be here smiling today if it wasn’t for him," George told PEOPLE at the event.