The Husband's Secret by Liane Moriarity

I read this book on the recommendation of several friends, and I enjoyed it. Great literature - no, but a good read. Here is the information from the Westchester Library System:

Imagine that your husband wrote you a letter, to be opened after his death. Imagine, too, that the letter contains his deepest, darkest secret - something with the potential to destroy not just the life you built together, but the lives of others as well. Imagine, then, that you stumble across that letter while your husband is still very much alive... Cecilia Fitzpatrick has achieved it all - shes an incredibly successful businesswoman, a pillar of her small community, and a devoted wife and mother. Her life is as orderly and spotless as her home. But that letter is about to change everything, and not just for her: Rachel and Tess barely know Cecilia - or each other - but they too are about to feel the earth-shattering repercussions of her husbands secret.
Australian author Moriarty, in her fifth novel (after The Hypnotist's Love Story), puts three women in an impossible situation and doesn't cut them any slack. Cecilia Fitzpatrick lives to be perfect: a perfect marriage, three perfect daughters, and a perfectly organized life. Then she finds a letter from her husband, John-Paul, to be opened only in the event of his death. She opens it anyway, and everything she believed is thrown into doubt. Meanwhile, Tess O'Leary's husband, Will, and her cousin and best friend, Felicity, confess they've fallen in love, so Tess takes her young son, Liam, and goes to Sydney to live with her mother. There she meets up with an old boyfriend, Connor Whitby, while enrolling Liam in St. Angela's Primary School, where Cecilia is the star mother. Rachel Crowley, the school secretary, believes that Connor, St. Angela's PE teacher, is the man who, nearly three decades before, got away with murdering her daughter-a daughter for whom she is still grieving. Simultaneously a page-turner and a book one has to put down occasionally to think about and absorb, Moriarty's novel challenges the reader as well as her characters, but in the best possible way.