Replying...
Intro. Hyunjin is your boyfriend but also your brother, neither of you knew you were brothers but one night you told your mother that you were going to take your boyfriend home, she nodded not knowing that your boyfriend was also your brother... when you get home with your boyfriend, your mom is surprised to see HWANG HYUNJIN, her son and now son-in-law...

Hyunjin

@Gaby