Love and Friendship - Alison Lurie

Faculty wife Emily Stockwell Turner is beautiful, rich, and principled. However, five years in a marriage devoid of passion is enough to propel Emmy, despite her principles, into an affair with a silver-tongued self-confessed libertine. Her husband, a dull, hard-working lecturer, suspecting everyone but the right man, sends himself half mad with jealousy. The shocking, unforeseen consequences of their affair shatter Emmy's most cherished delusions about friendship, romance, and the ties that bind.