Yeah, I've seen it with my own eyes, man. Monogamy's out there!
PS: Oh, wait, do you mean, like philosophically do I support it? That's a tougher question. I suspect that for most people, a kind of "flexible monogamy" is probably the best choice, but even that is rife with problems. There are people for whom "single mate for life" is the only way to go; there are people who would be best served in a group of five. Everyone's different. But you can't do any kind of -gamy without people being screwed up about it. The human race just don't roll that way.