To Tempt a Monster by Adrian Blue

In the city of Deathfall, cold weather only means one thing. Mating Season.
Etta lives to tease her guardian, Keen. He is impossibly proper, unfailingly genteel, and she wants nothing more than to see him snap. He hides his feral hunger beneath a suit of politeness, but Etta has seen glimpses of his beast. A wild, monstrous hunger that craves her as much as she craves him. After years of watching and waiting, can she finally make him lose control?
Keen’s eyes narrowed and in the next breath, he crowded her back against the wall beside the fireplace. His hands settled on the wall on either side of her head, each hand capable of crushing her with little effort. The idea should not have sent a thrill down her spine. Keen leaned down until they were nose to nose.
“Little temptress,” he growled.