He met his girlfriend's parents for the first time at an unremarkable restaurant in Pioneer Square. The year was 1995. What's so memorable about the occasion is how ordinary it was. He and his girlfriend showed up a little late. The restaurant was mostly empty. His girlfriend's mother sat next to her stepfather, and next to the stepfather sat her stepsister and her boyfriend. The food, the wine, and the conversation were all unexceptional. He learned about his girlfriend's parents, and they learned about him. All of this took about two hours, and at the end, the bill was settled by the stepfather. A year or so later, he and his girlfriend had a child, and not long after that, the two got married. All of this happened casually. There was no drama, no threats, no ultimatums. The two simply, quietly, effortlessly signed the paperwork that legally bound their relationship.

The man, of course, was me. I got married to a white woman, and this kind of union, an interracial union, happened without a hitch. In fact, I didn't expect any kind of hitch to happen. Not even for a second did it cross my mind, or hers, that there might be some resistance to our decision to marry. If someone on either side of our families objected to our marriage on the grounds of race, they would have completely caught us by surprise. Was this person out of their mind? Which planet did they live on? And if they were not an alien, did they not own a television or ever step out of their house? In our age and on this planet, scandal is more likely to arise from a considerable difference in age rather than a mere difference in race.

The strange thing in all of this, of course, is that interracial marriage was only fully legalized in the United States in 1967, two years before I was born (in an African-only hospital in what was then Qwe Qwe, Rhodesia). Even though this issue is full of queer writers writing about marriage and I am not queer, any discussion of changing attitudes about marriage has to include interracial marriage, as it's proof of how quickly attitudes toward marriage in America have changed before. In the current cultural atmosphere, it would be political suicide for a candidate of almost any public office to openly oppose interracial marriage. In the current cultural atmosphere, the union of a very white Heidi Klum and the very black Seal can be celebrated as one of the most perfect and happy marriages out there—indeed, what really upset and surprised people was not Seal and Klum's marriage, but the announcement of their divorce. Times sure have changed.

But let me point this out: My wife and I come from roughly the same class bracket. Her parents, like my parents, held advanced degrees and taught at universities or worked as professionals. As the geneticist Steve Jones has pointed out in several lectures and books, it is increasingly the case that class rather than race is the leading issue with interracial marriages. In London, for example, it's less shocking for a professional white woman to marry a professional black man than a professional white woman to marry a working-class white man.

But what does all of this tell us about the institution of marriage? It has never been stable. It is constantly changing. What many consider to be normal today—interracial marriage or even the marriage between an aristocrat and a commoner—was considered impossible, unnatural, ungodly not too long ago. Even monogamy hasn't always been stable; it's faced (and in some places, continues to face) competition from other modes: polygamy, polyandry, or simply no marriage at all. The only thing that's permanent about this important social institution? Marriage will always (and has always been) about the union of humans.