There are just some folks who think that nudity, in and of itself, is obscene. I disagree though. Nudity is nothing evil, though -- it's 100% natural. Americans tend to be puritanical and very uncomfortable with nudity in general. I don't understand why, but they just are.
So tell me who's more sexually moral? A person who is comfortable with the naked human body as God made it and does not equate nudity with lust, or someone who's on the verge of "pitching a tent" at the sight of a metal breast?