402.005 Definition of marriage.
As used and recognized in the law of the Commonwealth, "marriage" refers only to the civil status, condition, or relation of one (1) man and one (1) woman united in law for life, for the discharge to each other and the community of the duties legally incumbent upon those whose association is founded on the distinction of sex.
I understand most of this. As far as the government is concerned, marriage is a civil status. Other institutions, such as churches, can make of marriage something more if they want to. Marriage unites one (1) and one (1) to distinguish our monogamy from the polygamy that one might find elsewhere. Kentucky marriage unites a man and a woman, re-affirming, as the 2004 constitution amendment vote made clear, this state’s commitment to traditional heterosexual marriage. Marriage is for life, as least in hope. Marriage is both for the couple and for the whole community -- and a great boon it is to both, too.
Then we get to the mysterious part. What on earth does “duties legally incumbent upon those whose association is founded on the distinction of sex” mean?
What I would expect at this point in the sentence is, “sexual fidelity and the raising of the children they produce,” or something to that effect. I believe that is what “those whose association is founded on the distinction of sex” means. My best guess is that the General Assembly intended something like sexual fidelity and childrearing. They didn’t want to say that, though, so as not to exclude the childless, adoptive parents, and, perhaps, the maritally celibate. So it went through the legislative sausage grinder and came out with this choice legal euphemism, “duties legally incumbent upon those whose association is founded on the distinction of sex.”
If anyone knows the history of this phrase, I would welcome illumination.