What makes someone gay?

Someone is gay because that is the way he/she is born, one does not "become" gay

There isn't really a straight answer to this question. some people might say that bad experiences from someone of the opposite sex has 'turned them gay', but that's utter bullsh*t. You can't 'make yourself gay', you're either born with a homosexual tendency, or you're born straight, or indeed you're born with a bisexual tendency. But yeah, nothing can 'make' a person gay, they choose to be their sexuality. :)