I have. I met with a completely new-to-me therapist. Therapists are often willing to consult--I think it's good to be up front and say you're currently in therapy and want to consult about something going on in your therapy. And see if they feel comfortable with that. That could also lead them to not do a full intake session--the one I saw just had some basic questions, then we focused on what was going on with my therapist the rest of the time. It was helpful to give me perspective and validation. In fact, I may need to do that again soon, but with someone different.