Hugh Hefner's youngest son Cooper, 28, has tied the knot with actress Scarlett Byrne, 29, in a modest ceremony at a registry office in California.
The couple, who had been engaged since August 2015, posted about their wedding on social media and said they were planning a larger celebration in the coming months.
"Scarlett and I have made it officially legal and the two of us could not be happier," Hefner, 28, wrote on Twitter, announcing the news.
"Cheers to a life full of love, happiness, adventure, and great purpose, Mrs. Hefner."
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Byrne first gained fame playing the role of Draco Malfoy's friend Pansy Parkinson in the Harry Potter movie franchise. She has also starred in The Vampire Diaries and Falling Skies and in 2017 posed for the March/April issue of Playboy.
Byrne wrote on Instagram that she was proud to stand by Hefner's side as his partner, his friend and his wife.
"I cannot wait to continue building a life together. My heart is so full and I am so grateful for our love," she posted.
Cooper and his brother Marston were born to Hugh Hefner's second wife Kimberley Conrad.