How do you tell if someone who is naked under their heavy winter jacket is an exhibitionist or just a nudist? I think it depends on the conditions under which they will open their coat. Of course, that's assuming the unflattering stereotype that exhibitionism relies on non-consent, when it could be the case that the exhibitionist simply enjoys the secret knowledge of being naked under his coat without needing anyone else to suspect anything unusual. What if it's not the shock and dismay, but the mere fact of being naked (to one extent or another) in a crowd or outdoors or in a public place that the exhibitionist takes pleasure in? And what if that pleasure is not strictly sexual in nature (in the sense of causing sexual stimulation, and being used directly as a masturbatory aid), but just something from which the "exhibitionist" derives delight? Are we not then just talking about a nudist? Or is a nudist not allowed to "enjoy being nude" too much? If this is neither nudism nor exhibitionism, then what exactly should we call it? We have words for non-explicit, sensual eroticism, but we do not properly recognize it for what it is - non-explicitly sexual. If it has anything whatsoever to do with sex, it's forbidden. Call something "erotic" and the masses rush to cover their children's eyes, and toss it into the stigmatized bin of "pornography".
I know it's "dangerous" (for nudists, at least) to blur the line between sex and nudity, but I hope you'll see that the line between nudism and exhibitionism (and also voyeurism) is not so clear cut. I'm not saying that to justify any kind of behavior that is not appropriate in a nudist context, but to demonstrate why these subjects so often get tangled up. It's not some insidious strategy by a cabal of perverts. It's human nature. And while we can dictate the rules at a nudist venue (and we should!) - to preserve the decorum of civilized society - we should understand that there are not two distinct peoples in the world: nudists, and exhibitionists; and that, somehow, exhibitionists "just don't get it". Sometimes they overlap. Sometimes nudity is erotic. And sometimes it's not. There is room in this wonderful world for both - we must simply have faith that man can learn where and when one is appropriate and the other is not (and then assist in teaching him). There's no reason to pledge allegiance to one and disparage the other outright. Perverts tend to accept this more readily than nudists do - although that makes sense, since the latter has more to lose. But I'll take the truth over political posturing any day of the week. And twice on Sundays.