Is being gay hereditary, infectious, comes out naturally or a choice?

I am just wondering.. I hope I don’t offend anyone here. I have nothing against the third sex. In fact, I have friends who are gay and I find them funny to be with. But I often hear from people saying being gay or lesbian is hereditary. Being in the third sex is in the genes. Just like the saying history repeats itself. While there are some who say that third sex is infectious and that hanging out with them can be influential.

I’ve known some people in my neighborhood who are gays. Some showed signs when they were still kids and they have been gay since childhood. While some turned gay in their later years. A friend of mine hanged out with a group of gays and he turned into one of them after sometime. There is a gay who runs a beauty salon in my neighborhood and he told me that, he’s not really gay. He came from a poor family and he needs to support his mother. He posed as a gay just to be hired in a beauty salon until he was able to put up his own business and eventually he liked being gay.

These different situations confuse me. Which one could be it? What could be the real factor why a person could turn into gay? I am a bit concerned cause’ I have a nephew and in both of his parents’ blood, there are members of the family who are in the third sex. My nephew seems to have a liking in music for girls. He’s just 2 years old and I know it’s too early to say.

What’s your view about this topic?