Well, I have seen them. I'm in academic circles, maybe people in that setting, including gays, are more into stability, more into building relationships. (It takes a real ability to delay gratification to complete a doctoral degree.) Actually, I've seen statistics to the effect that about 5% of the gay population is in long-term monogamous relationships. (A larger fraction are in long-term relationships that are "open"; gay men in such arrangements often negotiate rules, such as "no emotional attachments outside the relationship" and "only safer sex outside the relationship".) Anyway, I still think, regardless of the true numbers, that monogamous relationships should be supported. Perhaps this is in the spirit of Lot, who bargained with the Lord about the destruction of Sodom: If there are only 50 good men in Sodom, will you spare the city?
Academia may be an exception . . . isn't it always? Folks in the "ivory tower" seem to play by their own rules.