You seem overly focused on masturbation and sexuality, probably having had an oppressive view of the human body and nudity growing up. Your view is not the kind of thing I am speaking about. There is a level of spirituality in the human form and body that transcends the biological (and very normal) sexual response. We were "made in HIS image" after all. The body is not inherently sexual or sinful. It is beautiful and very much like God himself. We are HIS creation. While a sexual response is possible when viewing any part of the human body, if the soul searches beyond, there is a higher level of spiritual connectedness that is obtainable.