I saw two therapists at the same time for almost a year and they did not know about each other. I kept planning on choosing one, but it did not happen until I decided to quit the one for other reasons. I did not find it to be a problem for me nor did I feel I "owed" either anything other than their fee. I may see two again at the same time. I like comparing the different approaches and it semed to make me calmer.

I have never heard a reason I found compelling for not seeing two at the same time as long as one is not trying to play them off of each other.