Bad Demon (Hellhound Heat, #1). Hellhound Heat, #1

It was Fern Honeycutt's eyes that gave her away. Not witch. All demon. Her coven saw her as an abomination, handing her over to pure evil. She escaped, but a lone female is an easy target. When breeder scouts start hanging around her store, the only way to protect herself is to break the rules she swore to uphold-adding a whole new problem. Relic, an emotionless and arrogant hellhound, witnessed those crimes and now he's stalking her.
But the unpredictable beast is the only thing standing between her and mortal danger, so Fern chooses the lesser of two evils and plays dirty, forcing him to protect her. However, the sinfully handsome Relic isn't easily controlled. He surrounds her with a quiet dominance and easy affection that's breaking through her pain-and as hard as she tries to protect her heart, he's even more determined to claim it.