Mated Enemies by Jordan Silver

He’s my enemy, it has been this way since the bond of the ancients and yet, ever since the first moment I saw him, I’ve wanted him in the most primal way. One look at him and my womb contracted as my body secreted its juices as if preparing to mate.
Thousands of years ago a vampire-fairy mating went very wrong, ending in the death of one and the permanent insanity of another, causing a rift between the two clans that has lasted until this day.
Now crown prince Lucien Star of the sky kingdom, home of the ruling clan of vampires who also rule over the rest of the immortal world finds himself imprinted on a fairy living in the human world. He has only seven days to bring her to heel or his life could go up in flames, literally.
But when he spies on her as she takes her early morning swim in the little lake beside her woodland home, he senses that there’s more to his future bride than at first glance. Something that can make an already dangerous situation worst: much-much worst.