The Sinner and the Saint (2 Book Series)

From Book 1:

Giving in to temptation would be the ruin of them all!

Having spent years believing a lie about his birth, Dr. Samuel Hastings has been condemned to a personal hell of his desire's making—his sinful thoughts of the one woman he can never touch would damn his soul for eternity.

Lady Evelyn Thorne is engaged to the very suitable Duke of St. Aldric when a shocking truth is revealed—and now Sam will play every bit of the devil to seduce the woman he thought would always be denied him!