It’s really strange to me that I haven’t seen articulated what seems to me the obvious reason why gay marriage isn’t the moral or legal equivalent of polygamy, and is not, therefore, bound to lead to it.
In a word: Two.
You can have sex with more than one person (like it or not, many married people do). I would hold that you cannot have full intimacy with more than one person (at a time, and it also takes time).
In fact, I’m not sure you can have full intimacy even with one person. It’s an ideal to strive for, to achieve at moments and at other moments fall far short. As the saying goes, we’re born alone, we die alone, and we’re often never more aware of our aloneness than in marriage.
But the point is, sex is only the opener, what overwhelms our resistance to getting close enough and open enough for the rest to start happening. If you stick around, then, it’s a full-time job trying to be intimate — and its daily double, companionable — with one other person. If you divide your attention you cut its depth in half and blow your focus. You may have fantasies about other people, you may be infatuated with another person, you may imagine that intimacy with that person would soar far above what’s possible with your current partner. Well, maybe: some people are better at it, or better together. But even at its best, coexisting with one other person, bringing two such different inner lives into one space, striking off the rough edges, takes a lot of work and time, a lot of attention, a lot of failure and rage and remorse, a lot of discovery and revelation of the other and of yourself. It’s not something we have the time or capacity to divide up and parcel out. If you do that (as in Big Love), it becomes something else — more reproductive and social, less . . .
At the core of marriage, underneath the habit and comfort and irritation, you bear witness to another person’s existence — and, let’s face it, you just bear another person’s existence — a little bit like God would. If we invented God (where would we get such an idea?), it was in the hope of being seen like that, through and through, with steady attention and patient, unblaming fascination, down to our dark places.
Try and do that with a harem, even a small one.