Homosexuality neither goes against nature, nor does it harm others. Nor is it "personally destructive." As a heterosexual, you are allowed socially sanctioned outlet for your behavior. But you're unwilling to grant homosexuals the same kind of socially sanctioned outlet (sexual behavior within the bounds of a formalized, committed relationship to another person).

But you haven't made anything like a compelling argument why we shouldn't. Rather, you've drawn a parallel between homosexual behavior and rampant adultery.

How does that parallel work, anyway? And why is it that gay people shouldn't be allowed to marry again?