"BABYGIRL IS MEDUSA!" he captioned a post on Instagram, adding a series of celebratory emojis including a snake.
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The Percy Jackson and the Olympians series is being created at Disney+ and Jessica's casting comes alongside that of Adam Copeland and Suzanne Cryer.
Walker Scobell was previously announced as the titular character as well as series regulars Aryan Simhadri and Leah Sava Jeffries.
Percy Jackson and the Olympians will tell the "fantastical story of a 12-year-old modern demigod, Percy Jackson, who’s just coming to terms with his newfound divine powers when the sky god Zeus accuses him of stealing his master lightning bolt".
It is based on Rick Riordon's series.
Jessica was confirmed on social media by the official account
Jessica will star as Medusa, the infamous gorgon, who will be seen as “wronged by the gods and bitter".
"Medusa lives in isolation until travelers stumble on her emporium. She is welcoming to some and a threat to others," the description by Disney reads.
Jessica is known for playing the roles of Melissa Glaser in the CW supernatural teen drama, The Secret Circle, Max on the Starz historical series Black Sails and Nora West-Allen on the superhero show, The Flash.
Ronen and Jessica have been dating since 2018
She has also appeared in shows such as the superhero series Smallville, MTV drama Kaya and teen series 90210.
Jessica and Ronen are believed to have begun dating back in 2018 and reside together in Los Angeles.
Ronen previously revealed how supportive Jessica was when he came out as bisexual in 2021, telling People: "It was the most supportive kick in the ass [to come out]. Sometimes it can be a lot to lay that onto your partner. It's not the easiest transition, but she's handled it beautifully and respectfully. Her support was all I needed."
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