In this article, A Marriage Form Will Just Be Icing On Our Cake – washingtonpost.com, a lesbian woman in California talks about getting married to her partner. In doing so, she gives an excellent explanation of why the institution of marriage is, literally, coming apart:
Over the last 10 years or so, as the country has been talking about same-sex marriage, and as my relationship with Ellen has evolved, I’ve come around to the idea that marriage isn’t one institution. Marriage is one word we use to describe a whole suite of institutions. Marriage is about money and property, love and religion, procreation and companionship. For most of history, nobody thought to distinguish between all of those different parts of marriage, because a wedding was the moment when a couple came together in all those ways. The day the priest blessed a couple, they became a single legal entity. That day, they moved into a new house together and had sex for the first time. The myriad distinct ways two people can put their lives together were rolled up in a single event.
In the past several decades, that has changed, for both straight and gay people. Couples routinely live together and have sex before marriage. Babies are born to unmarried women, mostly without scandal. Couples might buy a house together but keep separate bank accounts. A wedding, gay or straight, is not necessarily a moment of great transition so much as it is a simple marker of a years-long process.
I can’t pretend to speak for the people who are against gay marriage, but I think this is part of what they mean when they say that gay marriage will unravel the whole institution. Our national conversation about gay marriage has already shown how the different elements of marriage — legal, religious, romantic, economic, civil, procreative — have become independent. Any couple can decide to be romantic and economic partners, living together because they are in love, without a church wedding and without ever having children. We have friends, a straight couple, who have two children and a joint mortgage but are not legally married. Now, adults have the prerogative to mix and match the various things that make a marriage in whatever way they choose. It’s just that when gay people do it, it’s more obvious that “marriage” has already been deconstructed.