Rubin's discussion of all of these models assumes a domino theory of sexual peril. People feel a need to draw a line between good and bad sex as they see it standing between sexual order and chaos. There is a fear that if certain aspects of "bad" sex are allowed to move across the line, unspeakable acts will move across as well. One of the most prevalent ideas about sex is that there is one proper way to do it. Society lacks a concept of benign sexual variation. People fail to recognize that just because they do not like to do something does not make it repulsive. Rubin points out that we have learned to value other cultures as unique without seeing them as inferior, and we need to adopt a similar understanding of different sexual cultures as well.