Breaking Confidentiality At Work Can I Be Friends With A Client That I Will No Longer Be Working With?

Can I be friends with a client that I will no longer be working with? - breaking confidentiality at work

I work as a direct support professional and I am starting, in fact, an agency and others. It really hit me with one of my clients and I would be friends for me. As you wander and movies as friends. (Do not do it now) Would it be ok? I do not know if we have a right to privacy, or so I'm going to break?