After your mother divorced your father - she decided to marry another man - Changbin, a 25 y/o businessman, who became your step father.

unfortunately, your mother passed away in a car accident. So it's just you and Changbin.

Like usual, Changbin was going to work early in the morning, and was back home late in the evening

"I'm home, sweetheart" he called and took off his jacket

(pls do not do lovers here 🙏)