J.C.
There is nothing inherently sexual about the human body and that is important for kids to learn. As for when people should "cover up" in the home, that depends on how comfortable everyone feels, if people are uncomfortable their comfort should be considered, but if everyone is fine with a bit of nudity it is really not a huge deal. I myself am modest (only female in the home) because of my own discomfort but I would certainly never judge a parent that was less concerned about it.