Therapist consultant with each other all the time, and don't need our permission. I don't know if that is what happened. But, as another poster stated, he could have figured it out on his own, and may have slipped when he shared with you about your feelings for your current therapist. Your therapist is in therapy and anything he says is fear game to his therapist. If anything, it was his confidentiality as a client was violated, yet I don't suspect he will be distressed by it.

Sorry this happened to you.