What about the fact that everything has imperfections, even the female reproductive system?
What about the fact that seemingly every law in nature, has an exception?
Since imperfections are natural, homosexuality, by relation, is natural.
If you read the article I cited earlier, there is a great explanation as to how these genes pass on in the siblings of gay people.
Here it is;
"Important new evidence on a plausible mechanism for the evolution of "gay genes" has emerged from the work of Camperio-Ciani.
[23] They found in two large, independent studies that the female relatives of homosexual men tended to have significantly more offspring than those of the heterosexual men. Female relatives of the homosexual men on their mother's side tended to have more offspring than those on the father's side. This indicates that females carrying a putative "gay genes" complex are more fecund than women lacking this complex of genes, and thereby can compensate for any decreased fertility of the males carrying the genes. This is a well known phenomenon in evolution known as "sexual antagonism", and has been widely documented for many traits that are advantageous in one sex but not in the other. This provides solid experimental evidence of how "gay genes" could not only survive but thrive over the course of evolution."