When Jacob and I make love, there is a sorrowful kindness to his touch. “I married Caleb but I prefer Jacob’s company. Neither of them snores.” The two brothers keep switching places with each other, so that she is effectively married to two different people. They have the same physique, the same haircut, the same mannerisms. “It is nearly impossible to tell Caleb and Jacob apart. This one in particular is an attention-grabbing tale of a woman who is married to a man who has an identical twin brother. It is one of twenty-one stories in her debut collection Difficult Women. “My husband is not a kind man and with him, I am not a good person.” This is how the short story, The Mark of Cain, by the American writer Roxane Gay, begins.