This is as much a personal trait as it is a moral issue. You definately don't wanna lie, that's a moral issue. But how much you want to divuge, that depends upon you. If you are going to have a feeling that you are hiding something from your wife, then tell her those "secrets." If you are comfortable and don't think it is important, things that are not going to pop-up in future, then you can just keep it to yourself. Things you consider meaningless might be a big-deal for her; so be prudent while opening up.