The actor posted the news to Instagram Saturday, writing “It’s on!! She found a message in a bottle that washed ashore and said YES!!”
He shared a picture with himself holding up a handwritten note.
Mari commented on the photo, saying, “I love you!!” She shared it on her own Instagram, writing, “my heart is so happy.. I love you @joshduhamel.”
Among the well wishers was Duhamel’s ex-wife Fergie, who wrote in the comments section of his post,”Congrats!!!” The singer added six green heart emojis.
Fergie and Duhamel share a son together.
Mari was crowned Miss World America in 2016.