Slate and Shattuck, an art curator and director of Cuttyhunk Island Residency's writers program, first made their relationship public in January at Sundance Film Festival.
"He took me to France and made a picnic and made me feel happy and free and then he asked me to marry him and i screamed YES," Slate captioned her Instagram post. "I love you @benshattuck_art, you are the kindest and brightest and I am so grateful and here we go and keep going."
His announcement was similarly emphatic, writing, "In an abandoned castle in southern France, I asked this woman to marry me. 🌈❤️🍾Here she is in front of a door the color of her soul. In LA / MA / Holland / Belgium / France thank you @jennyslate and UP UP UP to more adventures."
The writing was on the wall back in June, when Slate appeared on Refinery29's Unstyled podcast and sung Shattuck's praises.
"I have this faith now — I do — that I can have this beautiful relationship with this man that I deeply love,” she told host Christene Barberich. “That I can have a full life, that I can live on this peninsula in Massachusetts where I live right now, and have my career, and that I can feel beauty in myself in so many ways.”
Slate was previously married to comedian Dean Fleischer-Camp, but the two split in 2016 after four years. She was last linked to actor Chris Evans, who you just know has already sent her a glowing, congratulatory text.