I don't think questions about sex are unethical at all if they are asked in context. I imagine there is a lot of hidden meaning behind sexual desires/fantasies and some T's may be keen to unearth them. I also feel that perhaps some T's have heard so much about sex from clients that their tolerance levels of what is and is not appropriate to talk about is lower than the general public therefore perhaps are not sometimes as sensitive as they should be when discussing this?

I had a T who asked me once if I masturbated..... I was telling her about some issues I was having in my relationship particularly in relation to sex. Whilst I was very awkward but relatively okay talking about sex I wasn't very comfortable at all to talking to her about that aspect of things so immediately said so and asked if we could change the subject. She made a brief joke/comment about it and then obliged. I know the question was in context but I still wonder it's full relevance.....