In a biological sense, you will find that the children of gay parents tend to have a mother and father too. Medicine has not adcanced beyond that.
As for parents in the sense of adult raisings children. The natural way of things is to raise children in an extended family. A nuclear family of father, mother, and two children is decidely unnatural, it is recent and geographically limited. Two gay parents is scarcely less unnatural than just two parents, or even one.
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