My daughter goes to therapy and was having some difficulty with her therapist. She wanted to cut back her frequency and her T did not want her to. My daughter and I go to a different therapist for family therapy, and in one session, this issue came up. We spent most of the session talking about my daughter's individual therapy and why she wanted to cut back and why her therapist didn't. It was actually really useful and helped my daughter clarify her own desires and feel empowered to seek further information from her therapist. The family therapist had good insights and advice and he didn't seem to think it was strange that we talked about this. It was helpful and I'm glad we did it.

Therapists are experts on therapy, so I think the idea is fine. Especially when you have been with someone for 10 years, you are practically like family and can develop, I would guess, some of the same disfunctions and blind spots that families develop over time. I think seeing someone for advice who doesn't know you or your T could be very worthwhile. But I think I also would share with my T something like, "I feel really stuck with our relationship and how therapy is going. When we try to resolve this, we end up at an impasse. I really want to move forward." I would just make very sure my T knew there was an impasse, and that I was frustrated and wanted to break out of the unproductive pattern.

Good luck.