I'm interpreting this to mean you are interested in both things, as the question was worded vaguely. In either case, you should try to open up lines of communication before falling into a pattern of fearing to communicate. Ask about his fantasies, ask about his turn offs. Rent movies with the things you desire in them, and watch his reaction when you watch them together. Establish communication foundations now, before you get married, so that they can continue throughout your marriage. If you are going to spend the rest of your life with this man, learn how to talk to him, trust in his love for you. If he runs away from you because of your spoken sexual fantasies, he does not deserve you. If you can't, or won't open up to your chosen life partner, then prepare for an unfulfilled marriage. Without communication, there is not a relationship. Marriage is pretty empty without a true relationship.