First off I have to say that a new Jess Michaels' book is now an auto buy for me. I find them to be quick, hot enjoyable reads.A Matter of Sin is no exception. What I liked most about this book is that it isn't the usual HR fare with the virgin and the man-whore. Not that I don't love those books, because the Lord knows that do but it is nice to change it up a bit once in a while. The other reason that I enjoyed this book so much.....no major angst or misunderstandings between the two main characters.Lady Isabel Avenbury is a widow who has spent the last few years seeing to the welfare and happy marriages of her two younger orphaned sisters. Her much older husband was a good man who took the sisters in and helped raise them. But now Isabel has determined that when her sister Serena is settled she will take a lover. She feels she is too old to marry again and of course there is the issue with her being barren.Seth Rowland, the Marquis of Lyndham has had to step into his dead brothers shoes and now he must find a suitable wife, who will give him heirs. His mother throws a country party to bring the debutantes out so he can make a choice.Of course the only woman at the house party who captures his attention is Isabel.I loved the interactions between Isabel and Seth. The sex scenes were sweet but smoking hot. I liked the way their relationship flowed and the fact that Seth had actually been interested in Isabel years before helps push the reader into believing they could fall for each other this quickly.All in all another lovely HR from Jess Michaels....I can't wait for the next book. As a fan of Julia Quinn and Lorraine Heath I found myself drawn to this series starter as the style and banter is reminiscent of those authors. Ms. Michaels joins their ranks by crafting an entertaining story where two immensely likable characters must choose between love and happiness or duty and obligation. Amidst this emotional struggle is unrelenting sexual tension, delightful and supportive friends, and heart-wrenching decision making that kept me on the edge of my seat until the very end.Isabel's life has been one of responsibility since she married at a young age. She married a much older man for the benefit of her family, and though he was kind, she sacrificed much for the welfare of her sisters. She sacrificed passion, excitement, and children of her own (though society blames the woman for her barren state) and has decided that she finally deserves more. Once her sister is married she can finally live for herself. A weekend in the country hosted by Seth Rowland is the first step towards her independence but takes an unexpected turn as she discovers the book all of Society is talking about, the Ladies Book of Pleasures. This book is an inspiration to her, though she refuses to admit it at first, as is the super sexy Seth. As the party progresses Isabel and Seth engage in a tryst that allows both of them a reprieve from the obligations that have weighed them down but when the party is over which choice will they make...? Isabel is immensely likable with thoughts and feelings we can all relate to. Her loyalty throughout the years makes her worthy of a HEA and I was rooting for her every step of the way.Seth too knows about obligations as the death of his brother leaves him to carry on the family name and a party in the country is his chance to find a bride. He's tired of obligations and as he meets each young lady he finds all of them unexciting, immature, as well as too predictable. The only woman to excite him is one Society tells him he can't have....the more mature Isabel, who he was attracted to when she first entered Society years ago. He's drawn to her sense of wonderment and her intrigue with wanting to walk on the wild side. He finds a kindred spirit in her and their sexual connection is combustible. Their tryst gives each of them a chance to be free for a short time but it adds even more heartbreak as their time together ends. They're a wonderful couple who both deserve happiness if they're just willing to take a chance on love. I enjoyed Seth's playful side that's fully on display when he's with his friend Jason or Isabel. He's charming with a sensual side that amped up the story's overall sexual tension and made for some very satisfying sexual encounters.Along with a great main couple with a crackling and combustible connection is a delightful cast of secondary characters. I adored Isabel's friends, Grace and Jacinda, and their unwavering support. They were colorful and outspoken in their friendship which was heartwarming to see. I look forward to these friends having their own stories told as they're both strong-willed women with intrigue surrounding them just hinted at. Seth's friend Jason is equally appealing as he's unrepentant in his love for the opposite sex. He's sexy, charming, and carefree but always supportive of Seth and their friendship was also a delight. I definitely look forward to seeing more of this playful cad in a future book as he's immensely intriguing. With delightful verbal banter and steamy sexual interludes the journey Seth and Isabel take is one that kept me engrossed in their outcome from start to finish and has me looking forward to the next installment in this sweet and steamy series starter.