Explain people who come out of the closet 40 or 50 years later
Explain people who go back to being straight after some religous retreat.
The facts are homosexuality has never ever been proven to be an inherited or genetic trait.
The fruit fly study has already been proven false and not even the same species and the twin study couldn't even conclude that even in twins when one decides they are gay in even 50% of the cases the other twin who shares the EXACT same genetic structure decides they are gay. Furthermore, the number went down even further when the twins didn't grow up together.
Its time to face reality. Your claims have absolutely no factual backing at all while people who come out decades later, change their sexual orientation back to straight give far more evidence that it is a psychological choice to become homosexual.
Heterosexuality is genetically inherited because only heterosexual sex allows any species to procreate.