Sir, sex is not what makes a marriage.  Doing housework is not what makes a marriage. Making dinner, raising kids is not what makes a marriage.

These things are part of marriage, sex is certainly important to marriage, but if you don't have one man and one woman, united in a formal commitment to each other, for life, whatever you have, you don't have a marriage.  The arbitrary whims of the five cannot change that. 

People can raise children without being married.  People can make dinner, clean, whatever, without being married.  

Your last comment is laughable for it proves too much.  If, in reality, gays have always been married, even without state recognition, why all the fuss?  Why demand that the state recognize anything? They believe they are married, they have what they think is a marital commitment to each other.  They express what they think is love for each other--so why all the fuss?  What difference does it make whether the state recognizes it then?