You say gayness is a flaw in the human genome. Please provide support. Your opinion is not evidence.
Google Gregor Mendel, and his laws of genetic inheritance. It is a mutation of a normal gene.
Okay:
With all species there is a dominant gene and recessive gene. Certain proclivities unique to the genetic makeup of each individual in a species. It is rarer to encounter a recessive gene in a species naturally, now with h.sapiens it would be natural to assume that homosexuality is a recessive trait given how little there are compared to the rest of the human population:
Of 238,574,670 adult Americans (as of 2012), there are
9,083,558 of those who are homosexual, that comes out to roughly 3.8 percent of the entire adult population (the number varies from 2 (using then entire US population) and 3.8% (using just the adult population). That leaves roughly an estimated 229,400,000 of those who are heterosexual.
So, just by population statistics, you can see the "gene" which causes homosexuality would be an inferior gene in the species, or a flaw.
More evidence:
Americans Have No Idea How Few Gay People There Are - The Atlantic
If it were a natural genetic non impediment, you'd think the gene would be more prevalent than it is, but it isn't. There's a reason for that. It is a flaw, an unintended mutation of the genetic structure which determines sexual proclivities. All mammals are driven to reproduce, all with the opposite gender. There can be no propagation of a species if a mammal, any mammal (humans included) is driven to reproduce with the same sex. It is genetically incompatible with the primary genetic make up of a species.
You cannot merge two X chromosomes or two Y chromosomes, you cannot fertilize one egg with another, nor can one sperm fertilize another sperm. Homosexuality is therefore not a natural part of the human genome.