It is a prurient sight, perhaps, but I'm not trying to photograph it in a vulgar manner, which would be all too easy to do. I just find it an interesting view, as a photographer of the human body, from an artistic and even scientific perspective, almost more so than a sexual one. The simple fact is, you don't usually get to see this angle because of our gymnophobic attitudes and sexual taboos.
Now, if we're being honest, not everyone looks good from this angle - not even I look good from this angle every single time. But I groom myself and photograph myself with the intent to create artistic bodyscapes that look pleasing enough to eat dinner off of. And when I accomplish that goal, there isn't a single reason in the world that adequately justifies preventing me from sharing that view with interested others. And (contrary to the specious "nobody wants to see that" argument) there are, always, interested others - if you know where to look.
