Boys that Bite — Mari Mancusi

Two sisters--as different as the sun and the rain. For one, getting into the Blood Coven is to die for. But for the other, getting out could be lethal...When Sunny McDonald gets dragged to Club Fang by her twin sister Rayne, she doesn't expect to find anything besides a bunch of Goth kids playing at being vampires. But when some guy mistakes Sunny for her dark-side-loving sister and bites her on the neck, she finds out that his fangs are real--and deadly.

Now, Sunny has less than a week to figure out how to reverse the bite, or else she's going to end up as the perpetually undead. And not only will she be a vampire, she'll also be bonded to Magnus--the bloodsucker who bit her--forever. And forever is a really long time...