waterfall dancing? did you mean the celebration with the Lizard tribe? the one where Rhot does the dance fight in glowing stuff? if you mean that how the actual fuck did you get through the virgin route without it? isn't it literally required for the ending where you actually sleep with Logan because you need the misty abyss?
maybe you've already done it? check the curse of lust page in the log in the book at the bottom of the screen. if it's done it should say something about the celebration in it. I'm gonna check to make sure i'm right about this tho