No Ordinary Mistress by Robyn DeHart
Remington Hawthorne, Earl of Latham, has spent his life protecting the Crown. When he's assigned to play the part of lover to Emma Masterson, one of the few female spies in England and the one woman he can't forget, he'll have to risk his heart as well as his life.
It isn't easy being an independent woman, much less a spy. Perpetually tasked with proving she is as valuable as any man in her profession, the last thing Emma needs is to be reunited with the one man who makes her want to forget her duties and get lost in passion.
Pretending to be his mistress isn't difficult - remembering that it is all a charade is a challenge. With every glance, every touch, every kiss, she is drawn deeper under his spell and pulled further from her goals. She refused him once, but it will take every ounce of strength to not give in to the passion that still burns strong...