Sure I don't deny that we are culturally biased<quoted text>
It is offensive because we have been long conditioned to 'think' it is offensive, and that is a big part of why it is offensive. People who lived their whole lives in the hot jungles and wore little or no clothing did not have a more serious problem with sexual abuse than those who always covered up so that our excitement by the human body was more aroused due to wondering what it looked like rather than actually seeing it.
Personally I find a woman in tight fitting clothes which basically gets your imagination going very erotic whereas many of them, if they were to actually be nude, might even nauseate me, because not all human beings have a body that is attractive naked.
Personally I think that Muslim women, who fully cover themselves, sometimes including their eyes, are setting themselves up just as much as scantily clad women, to be assaulted, because those who would assault them are going to want to see why they are covering themselves. There would be some exceptions to that, of course.
And if we were talking about just adults then this is a whole different conversation
But there simply is np justification for letting a child think it is ok for an adult stranger to be naked in front of him. How much easier does that make it for a pedophile to inititate the abusing process? Why do you think most of them start either by getting a kid drunk somewhere, watching porn, or using an environment like a lockerroom where it is more acceptable to be undressed? We start making everywhere acceptable and we better be prepared for what comes next because we will own part of that blame. We have a responsibility as parents, as adults, as humans, as citizens, and as a society to keep our young ones safe.