Lots of good responses....and I agree! I would be mortified and hurt to see a good friend of mine waiting to see my T right after I did and I know, whether I thought it was logical to feel that way or not, that I would struggle with jealous/envious feelings. I don't about seeing my T's next clients in the waiting room when I leave.....but if I knew them, different feelings, different story! And especially a close friend who ordinarily I might want to talk to about T experiences, who might want to talk to me about her T experiences........nope. It's important to feel that your time with your T and what your T says to you is special and to not have that feeling minimized by learning that maybe your T does/says the same thing in a friend's session....or wondering why something different is done for them and not you. Or what if one of you has something related to the other that you share....somehow, it would just feel like privacy/confidentiality was violated even though the T would be careful to guard that. My T knows that she sees other moms from a moms' group I belong to whom I would know and she is careful to not schedule us back to back so that uncomfortable situations like this are avoided...so it is not unreasonable at all for you to make this request of your T and to discuss with her how all this makes you feel. Or unreasonable to remind your friend that in the best interests of both your friendship and your therapy/therapeutic relationship with your T it's best to just keep your individual therapy stuff between the T and you and not bring it up when you're together if she's wanting to stay with this T too - it makes me think of the 'three's company' thing.
I wish you well in dealing with this! you really do seem to have a big heart and care about your friend and I hope she values that.