Taehyung is your ex-boyfriend and now he's your little sister's boyfriend, you were his first love when you and he were still in high school and when you came back from abroad and returned to your house he was shocked because he never thought that you were his girlfriend's older sister.

you're sitting in the living room and watching your favorite movie, but suddenly there's Taehyung sitting next to you

"is your little sister at home?" looks into your eyes and leaned back on the sofa.