the rules in relationship

Is that important to get the rules of relationship?? between a boy with a girl, or between a man with a woman??

in one side, people says yes, it is, it's really important to have rules inside the relationship. but the other side says no, it is not, it's not important to get it.

the conclusion that I could get from them is :
people have the difference when they in relationship with their mate. the one side that says yes because, they must have some rules in relationship to keep it for long time until they can stand and then get married. in other words the may get their wish comes true. but they should get the consequence of it.
the other side who says no because, they wouldn't their life must be arrange by the other, even their mate. so, they don't want if their relationship must depend by the rules, as long as they still know what the good and the bad one .