Sang-Hyun, who manifested as an Omega belatedly after joining the organization. Since he’s manifested as an imperfect Omega anyway, he intends to hide it for the rest of his life, but…

“Dad, please help me. No, wait, I’m fine…”

“…?”

He had just witnessed Do-Yun—whom he’d raised like a son for the past ten years—in the heat. He’d thought Do-Yun was just going through a belated puberty, but to find out he was an Alpha! And a dominant Alpha, no less. Worried sick that Do-Yun might become sterile, Sang-Hyun offers his own back passage for Do-Yun’s sake.

(Source: Bomtoon, translated)