The fact that homosexuallity exists is not proof of it being natural. Animals are driven by basic instincts, but they still have agancy, just like we do. They choose how to satisfy those instincts, whether it be natural or otherwise. One can clearly see this when one understands the purposes and works of God.

Because we have a higher intelligence, devine parentage, and devine potential, we must conquer the instinct for pleasure, and seek to satisfy it only in the natural way that God has set forth.

While I do not presume to know all things concerning God, I know he did not create homosexuallity, nor did he consider it when he created the world. This I know because I have read his words, and have asked what he meant, and he has told me.