Communities Rules About Sexual Conduct.

Rational Christian All religions have rules about sexual conduct.

Believer No, I said that I didn't feel that some forms of marriage are of equal dignity and honor as others.  I commented on aberrations from traditional, normative marriage.

All communities have rules about sexual conduct.

Right now in universities throughout the developed world are having vehement discussions and legal battles about what constitutes rape.  These all boil down to the issue of whether a man has the right to have sex with whoever he wants to.  Note that universities are generally secular institutions. 

These issues have nothing at all to do with the traditional definitions of marriage and adultery, just whether a woman has any choice in the matter. The issue of choice by women is why many religions are so protective of their normative marriage rules.   

In my ERSSG affirmatively consensual, non-procreative, responsible sex has few other restrictions or rules.  And cohabitation agreements may or may not be legally formalized and generally have little to do with sexual conduct.  

The exception is when a (usually) couple decides to include children in their relationship either naturally or by adoption.   At that point all of society's rules, laws, and traditions of marriage become important and the formalization of the relationship becomes imperative.  It is perhaps ironic that the religious marriage traditions which assumed lots of children a few of which survived to puberty, became an established legal structure in which to raise the few children required for replacement of ones memes and/or genes.