Clinical psychologist in training here. I’ve never been afraid, but my friend had a client once who made her extremely uncomfortable. Without revealing any information that could break confidentiality, I will say that he had issues with masturbating too much (and not doing much else), and at one point asked my friend if they could watch porn together in the next session so he could show her what he does… At another time, he talked about his masturbation habits while touching his d@#k through his pants a bit – totally inappropriate behavior, obviously. This client had lots of other issues, but when these things came up, her supervisor took her off the case because it wasn’t suitable for training and my friend didn’t feel safe.