Sometimes people are not useful

I had not told someone something as it would be rather unuseful for them to know this piece of information at this point in time (although they would need to know it at some point in the future). There were only three people who knew this piece of information. One of them told the person that I had chosen not to tell as it would be unuseful for them to know it at this point in time. Now I have to explain why I hadn't told them, and tell them more of the information than they would have needed to know when I was going to choose to tell them because this other person has told them some of the information. People!