This is not trivial at all. It is important to you! I believe everyone deserves their privacy, married or not! I do not know anything about the relationship you have with your husband so I do not understand his motives. A good relationship is built on trust and either he does not trust, or he is very insecure if he feels he must invade the little bit of privacy you want. You did not say whether you have confronted him! If you feel you can ask in a way that would not make him defensive maybe you could get him to understand how much your writing means to you. Let him know it is nothing against him, but just thoughts you are not ready to share with anyone.