Secrecy and betrayal are the same thing. Secrets rob agency, and the loss of agency is betrayal. When someone keeps a secret from you, they are deciding what information you are allowed to have. They are deciding what choices you are allowed to make. They are building a false world for you to live in.
You cannot make informed decisions about a reality you are unaware of. Betrayal can hurt so much beyond whatever is actually being kept secret. It is not only, "You did something that hurt me." It is also, "You knew this might matter to me, and instead of letting me decide what I wanted to do with that information, you made that decision for me." It is a violation.
The person keeping the secret gets to live with the full truth. The other person is forced to live inside a version of reality that has been edited for them. That is a loss of agency.
People sometimes justify secrets by saying they wanted "something that was just for them." But if keeping that thing requires hiding information that would materially affect someone else’s choices, then it is not simply personal anymore.
Discovering a secret can be extremely destabilizing. You are not just learning what happened. You are realizing that someone you trusted has curated part of your existence. They had agency. You were denied it. That denial is the betrayal.
Edited to add: Privacy is healthy. Everyone is entitled to boundaries, personal space, and parts of themselves that are simply their own. Privacy protects autonomy. Secrecy is different because it withholds information that affects someone else’s ability to make informed choices.
[This message edited by LittleMonk at 2:21 PM, Monday, November 2nd]