I have found the best allegory to homosexuality is left and right-handedness. We all have a natural preference. If, however, while developing, one is taught or forced to use the "wrong hand" (as I was for batting in baseball....my brother told me I was doing it wrong and would make be bat right-handed) - THAT becomes the natural way. However, with just a little practice, one can recover the "natural" original preference. (I practiced a little and can now bat or golf both ways).
The same can be applied to sexuality. A naturally hetero peron can easily be drafted into "gayness" during their early years. Many of these folks can change - and be completely happy (I personally know 1 girl and 1 guy wwho have done so). The term "L.U.G." doesn't exist for no reason.
Now, that being said, there ARE many naturally gay people. To try to change them would be a failure and a mistake. But, I would bet there are more "made" gays than "natural" gays...although I have no statistics on the matter....just personal observation.
But there's no scientific evidence that naturally gay people exist.
That is, there is no genetic test or procedure (experimental or otherwise) that can determine one's sexual orientation. When people claim to be gay and we believe them, what we're really doing is taking them at their word. We believe their claim, we believe their testimony and we believe their declaration that they are gay.
But there are some people who are suddenly skeptical when one claims to be ex-gay. They don't believe the ex-gay claim, they don't believe the ex-gay testimony nor their declaration that they are ex-gay.
When somebody uses a certain standard to measure the credibility of what one group says, but then refuses to use the same standard to measure the credibility of what another group says--thereby ignoring the claims of the second group (ex-gays)--he should ask himself why he believes one group and not the other... This is a double standard.
I would agree if they were born without the ability to reproduce (as a group - you can't debate being sterile is not a defect).
Which then would invite the arguement that they would have no sexual desires to begin with....