Naturist: Someone who believes that being unclothed is a natural state and would live this way if it wasn’t for society. There might be a natural or spiritual attachment as naturists often feel “at one” with nature and the world around them. Many naturists will say that there is nothing erotic about being nude, while others will claim that the kudalini energy and tantric energy that flows within them indicate that their sexual nature is tied to their naturism.
Nudist: A nudist is someone who gets naked situationally; a place that is safe. Examples might be at home, at a clothing-optional campground, or on vacation. Some nudists find being nude sexually stimulating while others do not. Being nude does not mean that the environment is necessarily a sexual environment (e.g. outdoors at a campground) whereas in some situations it does (e.g. the backroom of a leather bar.)
Exhibitionist: Someone who gets naked because it excites them to be seen by others — or the thought of them being caught by others. This doesn’t necessarily have to be a sexual high that they experience due to being seen, but often times it is.