Around the time of my parents’ 50th wedding anniversary, I turned to my father at the dinner table one night and said, “It’s amazing, Dad 50 years, and you never once had an affair. How do you account for that?” He replied simply, “I can’t drive.” Watching the governor of South Carolina cry like a little girl because his sexy e-mails got forwarded to his local newspaper, the State, made me wonder whether the real secret to a lasting marriage lies in limiting your means of escape