Oddly enough, the conversation about being born gay is one I've had with some of my own gay friends. I have had some pretty shady gay friends on FB that preach vehemently that it is fact.
I did my own research and found that the truth is scientists do not have 100% proof that this is true. The believe it to be the case but cannot nail down the gene's or proteins they believe to be responsible for being born gay. They are still searching.
My FB friend called me a slew of horrible names before defriending me because he felt I was just trying to be mean towards gays.
I am fine with people of the world pursuing the lifestyle of their choice as long as it's not forced on others .... just like my belief about religion as I am agnostic. I do find it weird that when you bring actual fact in to a discussion that some people just go apeshit because they know what you're talking about but don't want to admit the possibilities of it's accuracy at that point in time.
:)