After that first afternoon of frantic sex, Amber and I settled into a pattern. During the day, Amber puttered around her house and garden while David slept. Then, after dinner, as soon as David left for work, she slipped through the hedge that separated our yards, in my backdoor, and into my arms. I wasn’t a virgin by any definition of the word when I had my sister for dinner but sex had never been as exciting or as satis...