Gongyuganeung Sokkupchingu

Childhood friends Soo-Bin, Hee-Won, and Jeong-Heon, who were born and raised in the same neighborhood. Soo-Bin witnesses Hee-Won and Jeong-Heon having sex and cuts off contact. Nine years later, Hee-Won runs into him at a new company and, to make matters worse, runs into Jeong-Heon. After a brief moment of confusion, Soo-Bin is troubled by Hee-Won's suggestion that the three of them play together... Will the three childhood friends be able to maintain their relationship safely?

(Source: Bomtoon, transalted)