Self-reporting is just an expression of what someone believes, not what is fact.  Considering that all children have amnesia until age 7, there's a whole lotta forgotten environmental influences that likely account for what the homosexual perceives to be in-born.  While there is likely some genetic/epigenetic characteristics that make some more susceptible to same-sex attraction than others, it is all learnable/unlearnable.  And we know this as fact from people who have been one "orientation" and changed to the other.

Pederasty (opposite sex) is much more likely to be an inborn trait, as humans are able to reproduce much earlier than the laws defining "pederasty" consider.