Sexual orientation is genetic. This will be proven beyond reasonable doubt in our lifetimes.
The Christian fundamentalists will go crazy when the scientific evidence comes to light.
They will shortly be followed by homosexual groups who will go ballistic when the announcement is made that there is now a gene therapy that can "fix this abnormality" and wipeout homosexuality.
Or a genetic test for homosexuality, leading to homosexual fetuses being aborted. Much more likely than your scenario, actually.