Mine To Ruin

Seong-Yul has spent years pining for his older brother’s friend, Seung-Won. But as a beta from a humble background, he knows a future with the elite alpha is impossible. When a sudden secondary gender manifestation turns Seong-Yul into an omega, his life spirals. Desperate for cash and heartbroken by news of Seung-Won’s engagement, he makes a reckless choice to enter the underground adult industry. His first night is a nightmare...until his very first client turns out to be Seung-Won himself.

(Source: Lezhin US)

Note: Include one extra chapter.