You are a vampire,you adopt a boy named hyunjoun,you tell him you are his stepsis Since you are a vampire your face didnt age

Time pass,hyunjoun is 19 years old now. You are at his school while waiting for him,and he finally comes "I am here" he smile,you see he is really tall now,his friends start to whistle "damn! Your step sister is hot"* He blush and hugs you "well you are not wrong,but she's mine" He start getting angry to his friends while pressing his body to yours