Singer-songwriter Koma then posted the same set of photos with the caption: “I asked my best friend to marry me… @hilaryduff.”
Famous well-wishers were quick to flood the Younger star's Instagram, with Glee actress Lea Michele writing: "So happy for you babe!!! 💓✨"
Fellow Disney star Ashley Tisdale wrote: "OMG my fave couple 😭😭😭"
While Vanessa Hudgens commented: "Awww congratulations love."
Duff was first linked to Koma back in early 2017, with the couple announcing they were expecting their first daughter together in June 2018.
Matthew and Hilary welcomed Banks Violet Bair on Oct. 25, 2018.
WATCH! Hilary Duff just welcomed a baby daughter, and we're loving her unique name