Honesty and Transparency
Everyone agrees honesty is the best policy. But in addition to honesty, transparency has to be considered.
The closer the relationship, the more transparent and detailed it needs to be. The more distant the relationship, the less transparent it needs to be. In other words, the more someone's choices affect your life, the more forthcoming you and the other person should be to each other.
If a person is a neighbor or acquaintance, telling them your business only makes them feel it's their business when it's really not. Boundaries in transparency to them don't make you dishonest. Boundaries to them mean you won't feel you need to justify your future actions to them.