The Best Friend's Son

A swimmer pretends to join a training camp as an excuse to stay at his mother's best friend's house, secretly trying to get close to her. He orchestrates a scheme to expose his mother's affair with his target's fiancé, revealing their years of deception. As he gradually shows his affection, she struggles with the age gap and their complicated connection but slowly finds herself drawn to him. The betrayed pair teams up for revenge—sabotaging her fashion show, attempting a hit-and-run, and later drugging him to create a fake cheating scandal. They eventually kidnap her to force a business transfer. The swimmer sees through the plot, cuts ties with his mother, and rescues her in time, taking a knife wound to protect her. In the end, she reveals she is pregnant, and they decide to raise the child together, embracing their love despite outside judgment.