I can’t say this isn’t or has never been true, but the ideas people have are a gross over-dramatization of reality. These are by no means common practices for most Pagans.
Dancing nude, usually referred to as “going skyclad” is something that some Pagans do, either in private or in groups. However, it’s not something that is a standard part of their practices, and no one is expected to do it if they don’t want to. Some people have been Pagan for their entire lives and never taken part in a skyclad ritual.
For those who do practice skyclad, or attend skyclad rituals, it’s considered a beautiful and freeing thing. It’s not about sex or looking at naked people, it’s about being free and loving our natural form. It’s about being that much closer to oneness with their surroundings, without clothing in the way. While many choose not to participate in skyclad events for whatever reason, there’s nothing at all wrong with people who do. There’s nothing dirty or sexual about it.
As for orgies, this is something that would be incredibly rare. I suppose it might happen here and there, but it’s not common by any stretch of the imagination. Sure, there are mentions of orgies in history, but not all of them were attributed to Pagans by any means.
While most Pagans are pretty comfortable with their sexuality and are open-minded about sex, they’re not out humping everything they see or gathering for mass sex rituals. It just isn’t a thing. I suppose this idea stems from really uptight people taking Pagans’ comfort with sex and sexuality and expanding it to the extreme because they don’t like or understand the truth. No matter where it started or what keeps the belief going, it’s just not something that’s even close to common.
*Disclaimer: I no longer practice Paganism, but I’ve left these Pagan Myths articles active because I believe they’re still valuable in helping people to understand Paganism and reduce negative stereotypes.*