I agree that it is 100% your therapist's problem. I don't think a client should ever hesitate to say something because it might make the therapist uncomfortable. Isn't that one important reason people go to therapy, to be able to explore those things that can make others feel discomfort? And yes, I'm sure that sometimes therapists do feel discomfort, but again that's not the client's problem, and the therapist should act so as not to allow the client to notice it, in my opinion.

But a good therapist should not discuss their client in any way, unless it's part of their own therapy or their therapeutic supervision (and then the other T is bound by the same confidentiality rules.) I would view that as a serious transgression, that your T said that to his colleague.