I picked this up from my local half-price bookstore because I thought the cover was gorgeous and it was only a dollar. I can only say that I liked this book because the romance just didn't really do it for me. I think this is because the romance started out historically correct, rather than pandering to my modern romantic sensibilities. I can't help it. I want the romance (intellectual and emotional) to come before all the smexiness.
Julianne and Michael are brought together by an arranged marriage, and they start their familial duty of producing an heir for the duchy as soon as possible. Through their entanglements in bed and the pillow talk after, they realize that it just might be possible to have that long-sought-but-rarely-found sort of marriage within the aristocracy: a happy one.
What I found interesting was that both characters came from happy marriages, yet they didn't expect to have such luck themselves. I also kept looking for the reason why the book was titled “His Sinful Secret,” and while the answer wasn't what I expected, I wish there had been a little more punch to it.