I think you should discuss this with him very directly. It can indeed be helpful to get our opinions on this, but you will get even more useful information telling your T this straight out. Perhaps something like this: "T, we've talked about my fear of heights many times. When you suggest I go bungy jumping, it makes me feel like you were not even listening when I told you about my fear of heights. Do you remember us talking about that before? I feel hurt you don't seem to remember such an important thing..."

Then he can clarify if he has indeed forgotten or perhaps he has some other angle for seeming to have forgotten, such as wanting to introduce you to some new ideas you might not consider on your own. If it is the latter, then he could learn he needs to make those suggestions in a different way so as to acknowledge he has been listening to you all along. E.g. "I know you've told me about your fear of heights before, but would there be any way you would consider bungy jumping? I think it would be a really good experience for you because...." That seems much more validating to me.