My Stepson Is My New Alpha

When Eun-Woo marries his alpha coworker, Tae-Joon, he's ready for his own happily ever after. But all that changes when, one day, Tae-Joon brings home Joo-Won, his son from his former omega partner. Though Eun-Woo accepts and raises Joo-Won as his child, the marriage takes a turn, and after the divorce, Joo-Won is sent abroad. Ten years later, Joo-Won shows up, claiming he one-sidedly imprinted on Eun-Woo!

(Source: Lezhin US)