I told a friend about my therapist and how great she is when I was going through a particularly godawful time in my life. Later on my friend asked for my T's contact info when she was going through her own difficult life stuff. I had mentioned this friend a few times before in therapy, but she isn't central to my story. I actually talked about my friend's request with my T ahead of time, telling her that said friend might contact her and why I thought they would be a particularly good therapist/client match. My T seemed to appreciate the info, and she confirmed with me that I was comfortable with it. She said she wouldn't see certain people who were close to me (giving an example of somebody who I agree I would not want her to see), so I had the sense that she could refer my friend out without compromising my confidentiality. I do know that my T is (or at least was) seeing my friend now, but only because my friend told me.

Incidentally, because of my friend's rather specific job in our small city and the fact that she and my T have some professional contacts in common, my T knew my friend's first and last name the first time I mentioned her in session. So it wasn't a case where I could plausibly assume my T wouldn't make the connection. In pretty much every other case, I only just people's first names in therapy.