You have got to read Esther Perel's books "Mating in Captivity" and the "State of Affairs". Both are excellent and so helpful in understanding the deep and hidden meanings in our sexual fantasies and how we tick as human beings. Erotic fantasies do not make you a bad person. Its unrealistic to consider a lifetime of being with one human being that will meet all your sexual needs and you will never fantasize or consider the possibility of sex that doesn't meet social norms. That's the beauty of it! An active fantasy life is the key to keeping sex alive and exciting. Acting out fantasy with a spouse is incredible. But even if they aren't open to that, keeping a healthy fantasy life and imagination can be crucial to keeping your sanity. Thank God for these books and I have found them incredibly helpful to understanding behaviors and then using all this to improve life.