Cameron Diaz Goes Glam in Red With Husband Benji Madden at Gwyneth Paltrow's Engagement Party

Cameron Diaz took a break from her low-key lifestyle to celebrate love at Gwyneth Paltrow and Brad Falchuk’s star-studded engagement party.

The 45-year-old actress stepped into the spotlight at Saturday night’s bash alongside her husband, Good Charlotte guitarist Benji Madden. She turned heads in a crimson sequin wrap gown with a velvet bow and plunging neckline by Jenny Packham, along with a black bag with chain strap over her shoulder and dangling gold earrings. Madden, 39, donned a suit and bow tie in all black.

Diaz, who wed the musician in 2015, hasn’t appeared in a movie since the 2014 remake of Annie. However, a source recently told PEOPLE that she’s enjoying life out of the limelight.

“I can’t say whether or not she will go back to being a full-time actress, but for now she has other interests, causes she believes in, and time to pursue them,” the insider said. “Cameron has made a wonderful life for herself. Marriage agrees with her.”

Cameron Diaz and Benji Madden
Cameron Diaz and Benji Madden

Cameron Diaz and Benji Madden

Diaz feels “very fulfilled” by her private life with Madden, added the source.

“He came along at the right time in her life, and she knows she made the right decision to be with him,” the source explained. “Cameron has never had a romance like this one where it is feels like even ground.”

After dating famous men including Jared Leto, Alex Rodriguez and Justin Timberlake, Diaz found her match in Madden and took a step back from the spotlight around the time of their wedding.

Her lower profile caused Selma Blair to suggest in a recent interview that her The Sweetest Thing costar is “done” with show business, though Blair quickly clarified her comments on Twitter, writing, “CAMERON DIAZ is NOT retiring from ANYTHING.”

Benji Madden and Cameron Diaz
Benji Madden and Cameron Diaz

Benji Madden and Cameron Diaz

In recent years, Diaz has shifted focus from acting to wellness ambassador. In 2013, she released the bestseller The Body Book, followed by 2016’s The Longevity Book, in which she shared her secrets to aging beautifully.

“Her years with Benji have been enlightening for her,” said another Diaz source. “She has become a new person with more self-confidence and grounding. Cameron needed something different in her life, more substance and a relationship where she felt loved.”

The couple “would like to have a family,” the pal added. “They are very happy and enjoying their lives together.”

The actress turned 45 last August and received a sweet Instagram dedication from Madden. “Happy Birthday to my Beautiful Wife. I feel like I am the LUCKIEST guy ALIVE,” Madden wrote alongside a photo of him and Diaz enjoying a romantic boat ride.