I'm not an AA 12-stepper, but this reminds me of an area I have been very much into and which came up many times in my life, and I have been on both sides. The question could be: can a close friend or significant other be our effective psychotherapist or psychiatrist? I have been good friends with and also dated a good number of people in these fields because mental health is also one of my primary interests and my own profession now. The answer, for me, is no. I would say, if they can be unbiased enough to play the role well, then the intimate relationship is probably not intimate enough... and if it is, then trying to detach from a partner in order to be able to be such a guide may harm the relationship. What I do believe though, and like very much, is discussing issues, developments, ideas, dissecting how things go, and if there is a high level of mutual trust, it can work wonders... but it's very different from a hierarchical sponsor-sponsee or psych-patient relationship that, in my mind, is more like a teacher-student relationship even if there is a lot of what's called transference in it. I personally would not even want to share a sponsor or a therapist with my significant other, I think it would get in the way of the efficacy if for nothing else, on the level of mental processes in the head.