Honestly, you can admire how someone looks, without it being a sexual thing.
I took life drawing for a number of years. The first few sessions were awkward, with nude models (mostly women). Over time, it was less and less of a deal. You could be standing there, talking to the model while she was in nothing but a cotton robe, she was completely nude moments before, and you're just talking about art or something on campus or whatever. NBD. You can learn to see the beauty in the lines and form of the body, without it being sexual at all.