What is sacred in a marraige?

My husband tells his friends everything about our finances, what we do, what our plans are etc. I tell him that there are some things that he should not just discuss with everyone, he does not see anything wrong with it. I purposely have to keep some things from him because I know he will just sit around and gossip about it with his friends. His friends do not tell him anything about their personal lives they just listen to him and comment on his.