A lot of forums or web sites that I have read have a lengthy discussion on the Scripturality of non-sexual nudity. I don't want to go over the same ground that they have done so very well, but will point you to some of them.
My favorite site is the Fig Leaf Forum with its in-depth look at nudity and what the Bible says - or doesn't say - about it, specifically the article entitled Clothing and Nakedness in the Bible.
Another site of an individual that has written some very insightful books is that of Jim Cuningham. I very much enjoyed reading his book "Nudity & Christianity". Jim is a very devout Catholic like myself but he brings quotes and information from all segments of Christian life into his book. He doesn't make it denominational and uses all aspects of good Biblical study to show that non-sexual nudity can be very Christian.
Some people say that you can take any Bible quote and twist it to mean anything you want it to. I agree and that is why I am not putting any specific quotes in this post. I want you to look at the articles I have listed and see that they not only make the statement that nudity is not opposed in the Bible, but that they follow that statement with a lot of research and follow-up to continue that idea.