I'm just going to completely ignore the above post. On the regards of homosexuality, choice or genetics, I think its entirely environmental. Based on where you grow up and the conditions that influence you. As for what Dalir said about how homosexuality isn't the default state of human beings, I think heterosexuality isn't either. Tabula Rasa. Blank slate. When you are born, your mind is a blank slate, ergo, everything environmental affects you. This brings us back to the whole nature vs nurture debate, which I won't go into at the current time.
Final sumnation, homosexuality isn't a choice, nor is it dependent on genetic 'defects'. It's based entirely on your environment.