Myla by Moonlight

Magic bites... Created at Prince Taric's birth, Myla is a spell, an enchantment designed to appear and protect him when he needs it most. She has always been content to do her duty...until one night of forbidden passion leaves her longing to experience life--and love--as a mortal woman. Yet the risk is too great. Even if her blood runs as red as his, she can never give him the one thing he needs: a child. Taric's blessing--and his curse--is knowing the kingdom's future depends on his producing an heir to continue the bloodline. His bond with Myla has always been that of protector and protected. When it suddenly becomes something much more, he unwittingly sentences his people to certain death. An old enemy is plotting to destroy all he holds dear: his lands, his people, his father, and his lover. And this time, even if they fight tooth and blade, their shared magic may not be enough to save them...