'Empire' Stars Grace Gealey and Trai Byers Are Engaged

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Fantastic news for the Empire family!

Costars Grace Gealey and Trai Byers are engaged, ET can confirm. Trai, 32, reportedly popped the question on Grace's 31st birthday on Sunday. The photogenic pair has apparently been dating since the hit Fox show first started shooting, though they've both remained tight-lipped about their romance.

A source tells ET that Grace's birthday party at the Kinmont restaurant in Chicago was actually a surprise from Trai, and that the engagement most likely happened earlier in the evening. "She looked like a princess wearing a beautiful pink dress to her birthday and was glowing all night," the source adds.

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Trai also Instagrammed pictures of Grace's memorable birthday celebration on Monday, noting that it was an "unforgettable night."

"Had so much fun celebrating @gracegealey's life!!" he wrote. "Happy Birthday to an exquisite human being! Thank you @kinmontchicago for hosting us. Amazing spot, wonderful food, UNFORGETTABLE night."

Trai plays Andre Lyon on Empire -- the son of Lucious Lyon (Terrence Howard) and Cookie Lyon (Taraji P. Henson), while Grace actually plays Lucious' ex, Anika Calhoun.

Congrats to the happy pair!

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ET caught up with Taraji P. Henson in February, when she explained why her now-beloved character, Cookie Lyon, is the queen of primetime. Watch below: