The overwhelming majority are NOT in a "stable" relationship, and most of them are very unhappy. Maybe dance and the arts attract unhappy homosexuals, I don't know. The guys that my mom used to cite as an example of a "long-term relationship" parted company after 5 years . . . and it turned out that they had had a lot of issues all along.
I'm sure there are some long-term relationships somewhere, but I haven't seen them.
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?