Entertainment Movies Allison Williams and Alexander Dreymon Are Engaged, He Confirms in Sweet Tribute: 'My Gorgeous Fiancée' Allison Williams and Alexander Dreymon share a baby son named Arlo By Benjamin VanHoose Published on December 9, 2022 05:16 PM Share Tweet Pin Email Allison Williams is engaged! On Wednesday, the Girls alum, 34, made her red carpet debut with Alexander Dreymon at the Los Angeles premiere of her new horror comedy M3GAN. In an Instagram post Friday documenting that night out, Dreymon, 39, said he was "so proud of my gorgeous fiancée," confirming they are actually engaged. The Last Kingdom actor wrote alongside photos from the event, "Premiere of M3GAN with a screaming, laughing, cheering crowd. It's the ultimate fun scarefest. I'm so proud of my gorgeous fiancée @aw. Congratulations to everyone who worked so hard on what will likely be a new cult hit." Celebrity Engagements of 2022 Alexander Dreymon and Allison Williams. Jon Kopaloff/FilmMagic Never miss a story — sign up for PEOPLE's free weekly newsletter to get the biggest news of the week delivered to your inbox every Friday. The couple has been together since late 2019 after meeting on the set of the Swedish thriller Horizon Line, which premiered in November 2020. The two welcomed son Arlo last winter. News first broke back in April that Williams and Dreymon secretly welcomed a baby when the two were spotted enjoying a vacation with Arlo and Allison's father Brian Williams at a private resort in the Abaco Islands of the Bahamas. Jon Kopaloff/FilmMagic "They seemed to be very happy and very much in love," a source told PEOPLE at the time, noting that the Get Out actress appeared to be wearing an engagement ring. (Reps for the pair declined to comment at the time.) Insiders previously told PEOPLE they chose to keep news of their child 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 a source. "But they're over the moon." M3GAN is in theaters Jan. 6.