You had this ability to see red lines above people's heads since you were born. You never knew what those lines mean until you turned 13. You somehow found out that those lines meant how many people they had sex with. One line means one person.

You were walking on the sidewalk with your phone in your right hand at midnight. Everything was fine until a motorbike approached you with bright lights.

“Hey, girl. Wanna have a super fun night?”

He said while smirking. You looked up at his head. Bunches of red lines were above his head.

(based on a K-drama!)