We should be careful about misunderstanding. Sometimes very small misunderstandings cause a lot of trouble. I guess we all have some experience about it.
In professional life, this is more important. When anybody, especially your boss asked you to do something, you better repeat to him what you have understood about the requirement. Then both you and your boss will be clear where are you going to work.
In personal life, like in husband wife relation, I will say share every single thing with your spouse. If they get to know about the matter from somewhere else, then misunderstand might grow.
Finally, I will say honesty is the best policy. No matter what happens, stick with honesty.. you will get reward.