Mine for Eternity by Megs Pritchard

Hunter thought his inside man was expendable, a necessary evil to get ahead of the vampires. A man he could exploit to the fullest and dispose of, if needed.
When he walked into the hotel room, all his plans immediately changed. The mole was not the vampire he’d assumed he’d meet, but a human and fates most precious gift. The man was his mate.
For years, Carter had been forced to work for the vampires, a species he truly despised. He had no choice. If he wanted his parents to live he had to do what they wanted, but that didn’t mean he couldn’t try to bring them down from the inside.
When he finally agrees to meet the man attempting to hack into his security systems, he’s stunned by his reaction. He didn’t expect to meet a vampire who he would have such a strong attraction to or the fact that he turned out to be the vampire’s mate.
Deciding to mate, Carter leaves and Hunter lets him, but will they meet again, or will the vampires find out and make Carter pay the ultimate price?