Kate Mara revealed she's pregnant with her second child with husband Jamie Bell on Sunday afternoon in a subtle, yet sweet Instagram post.

"There's three of us in this pic," the 39-year-old actress captioned a photograph of the couple from a night out in London.

Mara used an image from the BFI Chair's Dinner awarding BFI Fellowships to James Bond producers Barbara Broccoli and Michael G. Wilson at Claridge's on June 28, 2022, in London, England. 

She tagged a Jamie Bell account which had 5,000 followers, no posts, and followed Bell's best friend, Max Minghella.

Kate Mara said she was pregnant on Sunday with Jamie Bell

Kate Mara noted there's 'three of us in this pic' she shared of husband Jamie Bell from the BFI Chair's Dinner awarding BFI Fellowships to James Bond producers Barbara Broccoli and Michael G. Wilson at Claridge's on June 28, 2022, in London, England.  (Ricky Vigil M/GC Images)

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Mara and Bell welcomed their first child in May 2019, but have yet to reveal their daughter's name publicly.

A slew of their Hollywood friends congratulated them on the understated announcement.

"Awwww congratulations loves!!!!," Jenna Dewan wrote, while Michael B. Jordan added a host of star emojis.

Octavia Spencer, Michael Pena, Andrew Rannells and Lara Worthington all sent warm wishes to the couple.

Kate Mara revealed she's pregnant with her second child with husband Jamie Bell

Kate Mara and Jamie Bell attend the BFI Chair's Dinner awarding BFI Fellowships to James Bond producers Barbara Broccoli and Michael G. Wilson at Claridge's on June 28, 2022, in London, England. (David M. Benett/Dave Benett/Getty Images for British Film Institute)

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"The cats out the bag," celebrity fashion designer Johnny Wujek wrote. "Johnnys a fairy god father again. Can’t wait. Congrats my loves."

The couple first met on set of the Marvel Cinematic Universe flick, "Fantastic Four," in 2014, where she starred as Sue Storm/The Invisible Woman while he played The Thing.

Their relationship was kept mostly quiet until they were seen together at the MET Gala in 2015.

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Mara, the great-granddaughter of the founders of both the New York Giants and the Pittsburgh Steelers, announced their engagement in January 2017 in a tweet showing off football gear from both of the teams.

Months later, the notoriously private couple married in Los Angeles. They each posted the same photo online to mark their July nuptials, and Bell went with the caption, "Me and Mrs. B."

Bell was briefly married to Evan Rachel Wood from 2012-14. They share an 8-year-old son, Jack Matfin Bell.

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