Allison Williams and Alexander Dreymon Make First Red Carpet Appearance After 3 Years Dating

Allison Williams and actor Alexander Dreymon have officially made their red-carpet debut!

The Girls alum, 34, and her 39-year-old German partner stepped out at the premiere of the sci-fi thriller M3GAN at the TCL Theatre in Hollywood on Wednesday night.

For their night out, Williams sparkled in a sleeveless, sequined gunmetal-hued gown and wore her hair down, while Dreymon sported a double-breasted dark plaid suit for the night out.

The couple has been together since late 2019 after meeting on the set of the Swedish thriller film Horizon Line, which premiered in November 2020. The two welcomed son Arlo last winter.

RELATED: Allison Williams and Alexander Dreymon Welcome First Baby, Son Arlo: 'Over the Moon,' Says Source

On the red carpet, Williams and Dreymon posed arm and arm for photographers. He even sweetly kissed her cheek at one point.

Jon Kopaloff/FilmMagic

In the new movie, Williams stars as a roboticist for a toy company who gifts her grieving niece (played by The Haunting of Hill House's Violet McGraw) a full-sized A.I. doll named M3GAN after the girl's parents die.

But what starts as a friendship grows scary when it quickly becomes apparent M3GAN is a little too protective over her.

"M3GAN is a marvel of artificial intelligence, a life-like doll programmed to be a child's greatest companion and a parent's greatest ally," reads an official synopsis for the film. "Designed by brilliant toy-company roboticist Gemma, M3GAN can listen and watch and learn as she becomes friend and teacher, playmate and protector, for the child she is bonded to."

RELATED: Allison Williams Makes First Public Appearance Since News She Welcomed Baby Boy

Jon Kopaloff/FilmMagic

Meanwhile, news first broke back in April that Williams and Dreymon had secretly welcomed a baby, when the two were spotted enjoying a family vacation with baby Arlo and Allison's father Brian Williams at a private resort in the Abaco Islands of the Bahamas.

"They seemed to be very happy and very much in love," a source told PEOPLE, noting that the Get Out actress appeared to be wearing an engagement ring (Reps for the pair declined to comment).

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Dreymon is best known for playing Uhtred of Bebbanburg in the Netflix series The Last Kingdom, which wrapped filming in Hungary earlier this year.

Insiders previously told PEOPLE that the parents chose to keep news of their new addition quiet. "They are both private people individually, and they made the decision to keep this happy news to just a small circle of family and friends," said the source. "But they're over the moon."