The Vampire's Siren

Carmen is just a normal high school student. They joke around with friends, snap back and forth with their sister... They fall in love with a boy. A boy who has eyes for another boy.
Then one day, at a party they meet the rudest jerk... And then finds him in their class the next day.
They have to show the jerk around, and eventually he makes his way into their friend group.
But something changes in Carmen, when the jerk exposes that he's actually over four hundred years old, and they're his siren.