I don't think it is a good idea for therapists to become friends with clients after therapy at all. I have ongoing email contact with my ex therapist, but it is definitely not the relationship of 'friends'. She maintains her professional role in her communications with me, and I honestly wouldn't want that to change. Changing the dynamic of our relationship would be harmful, I think.

She is not my 'friend'. She doesn't share about the intracacies of her life with me and I don't ask her to. What she is to me now is a human being who knows more about me than anybody else in the world, who holds me in unconditional positive regard, and who is caring and generous enough to offer me continued support and interest and love. (To be clear I will add that her 'love' is not offered in any form other than the support she continues to give me willingly and without financial reward).

But we are not friends, and we will never be 'friends'. She is my ex-t and our current relationship strongly reflects those roles.