If all men were gay then is being gay a choice? Serious question.

Willingness to have sex with another male is not being "gay". Attitudes towards gender and sex are not just a new thing, many cultures, historically, have had far more fluid concepts of these things.

Willingness to have sex with another male is literally the definition of homosexuality. What are you talking about?

"Willingness to have sex with another male" does not preclude willingness to have sex with a female and therefore is not the definition of homosexuality.

where do you get the idea that all men were gay? and no, being gay is not and never was a choice. one can have sex with people (of the same sex) even when they're not attracted to them but that doesn't make them gay.

counterpoint: a lesbian is able to have sex with a man but that doesn't make her straight either.

So then except in a small minority of cases (less than 5-7%) these “pedophilic” relationships were not really sexual at all as the author claims.

If all men are gay, it is practically impossible for that to have happened as a result of voluntary choice.