NAE GEOT

Choi SungHyun, handsome face, stellar grades, the perfect son anyone would envy... But in reality, he hides his poverty, surviving off the money of wealthy lovers? Then Kang Jun suddenly appears before Sung-Hyun. Betrayed that Sung-Hyun doesn't remember him,
he gradually tightens his grip, becoming obsessed, and eventually even confines him...

(Source: MrBlue, translated)