Anger is a learning opportunity for your therapist--to learn more about you and why you are triggered, to learn about your communication patterns, etc. My T has told me that client anger arouses in him a feeling of curiousity, and of progress. Ah, hmmm, we've uncovered something of importance, let's explore this and find where that anger is coming from.... I can almost see his ears swivel forward, like a horse, at the slightest hint of anger, and he turns his body to me in a very open posture, and sits forward on the edge of his seat. It's his "I invite you to tell me more" body language. I bet my T did not respond this way, though, when he only had 2 years experience.