Until the Sun by Chandler Morrison
A young hospital security guard with a disturbingly unique taste in women. A maternity doctor with a horrifically unusual appetite. When the two of them meet, they embark on a journey of self-discovery while shattering societal norms and engaging in destructively aberrant behavior. As they unwittingly help each other understand a world in which neither seems to belong, they begin to realize what it truly means to be alive...And that it might not always a good thing.