Forgive me, perhaps I read too much into the word, "heterosexual". Other than being able to have children the old fashioned way, what really distinguishes the heterosexual family from other types of families, say, an adult son or daughter who lives with an elderly relative?
I don't fear monogamized gay people setting up stable households, where they mow the lawn, pay their taxes, and contribute to society in much the same way as heterosexual families do.