I think the important thing is that it made you uncomfortable, and to let your therapist know that the question makes you uncomfortable and why it does. The phrase "touching yourself" skeeves me out personally (I would actually probably say that).

I guess perhaps the question is whether you are uncomfortable about the topic itself, but the therapist is competent and ethical enough to help you, or if the therapist is triggering a red flag and you should move on.

If you don't feel comfortable asserting yourself to this therapist, then that might be something to consider.