I think the answer is that it can't. This topic has been discussed on this board before, and in fact, when I googled "I am seeing two therapists", the results included a couple of other psych/therapy boards where the same questions have been asked and the same excuses for doing it have been offered. I've seen people claiming that just because therapists say it can't be done, doesn't mean that it can't be helpful to someone. However, I haven't seen any evidence where someone comes forward and claims that this approach (as opposed to a teamwork approach where everyone knows about it) has been helpful to anyone at anytime.

If other intimate relationships, such as marriages/partnerships are any guide, those who are into polygamy argue that it only works if people are honest with each other. I could personally believe that just about any kind of relationship could work for anyone, as different as we all are, but I've never heard anyone suggest that dishonesty is the root of positive relationships of any kind.

Anne