Homosexuality is not a genetic defect nor just perversion either. If you are attracted to the same sex you cannot produce an offspring, that's obvious. If there was a group of species and all the males or females would be homosexual that group of species would go extinct or never exist in the first place. But it doesn't mean it s unnatural. Many other species show homosexual tendencies. It is not only the need to reproduce that it is natural, it is also sexual desire.