Josh Duhamel Seemed 'Gloomy' After Fergie Divorce, New Fiancée Audra Mari 'Cheered Him Up': Source

David Crotty/Patrick McMullan via Getty Josh Duhamel

Josh Duhamel and his new fiancée Audra Mari found "something special" together, a source tells PEOPLE.

The 49-year-old Love, Simon actor revealed on Instagram Saturday that he and Mari, 28, got engaged in a sunny beach proposal. He wrote alongside a happy photo, "It's on!! She found a message in a bottle that washed ashore and said YES!!" On her page, Mari said, "my heart is so happy. I love you @joshduhamel."

The engagement comes over four years after Duhamel and Fergie broke up in September 2017. The "Fergalicious" singer then filed for divorce in May 2019 after eight years of marriage. Their divorce was finalized in November 2019.

A source tells PEOPLE that Duhamel was in a sad place after the divorce from Fergie, with whom he shares 8-year-old son Axl, but Mari made him happy when they began dating in 2019.

"You could tell that they had something special early on. He introduced her to his friends right away," says the source. "He seemed a bit gloomy after his divorce and Audra definitely cheered him up. She came into his life at the perfect time."

"They live a pretty quiet life in L.A. They often grab dinner in Malibu and walk on the beach. They have friends over for barbecues," the source adds.

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Fergie even congratulated Duhamel on his engagement, writing in the comment section of his Instagram post, "Congrats!!! 💚💚💚💚💚💚"

In December 2019, a source told PEOPLE that Duhamel was "really happy" with the former Miss World America. The source's comment came amid a holiday party the two attended together that month, at which Duhamel and Mari "were basically together all night," an onlooker said at the time.

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During a 2018 episode of Dax Shepard's Armchair Expert podcast, Duhamel opened up about what he was looking forward to in the next stage of his life — including settling down again after his separation from Fergie.

"I'm not 30 years old anymore. I'm 45. I want to have more kids in the next few years," the Transformers actor said at the time. "So it's more about finding someone young enough to have kids. It's not as if I'm out there trying to just f— anything. That's not who I am. I'm trying to find a girl that I can be with and have a family with."