I've had dreams about my former marriage counselor and current therapist. One that I've had multiple times has involved being in session with them, then other random people are coming in the room and sitting down, and the therapist doesn't seem to care.
I think in terms of telling them about the dreams, it would maybe depend on how they feel about dreams in general. The fact that they seemed horrified by the one suggests that telling them might not be helpful. Though if you think maybe they represent someone or something else in the dream, that might be helpful to talk about.