Dear Megan:

I would say: don’t confront this person about his/ her behaviors. But stop initiating contact, stop responding to initiation of contact, of get together and stay away, melt into the background of this person’s life.

This way you minimize the chances of revenge by avoiding confrontation and at the same time you no longer engage in a relationship with the person who is harmful to you.

One more thing: about the secret, see if you can do something in that regard, independently of the now ex friend (ex because a friend is someone you trust). You wrote that the secret is not something illegal, well… decriminalize it. Make a reasonable, wise effort to bring it to the light.

anita