In watching The History of Sex on The History Channel, homosexuality is as natural as heterosexual intercourse.
Taken out of the abstract concept of Adam & Eve, reality shows us that homosexuality is as old as heterosexuality. This makes it natural.
The antagonism against homosexuality is competitive in nature and is ultimately used rise one's own status above others in the attempt to win. It's an easy target, and simple logic is penises go into vaginas to make a baby. Reality is much different. And reality can be found today, and in history for 1000s of years. That reality is open sexuality.
The point is everyone can have a viewpoint on their own sexuality. And applying logic to it ends it having sex only to make a baby, and extending logic to family, to have that close group of individuals dedicated to bonding with this child.
This is logical to the extreme.
However, there is more going on that just being animals. The awareness of a human being is different than of other animals, and different animals exhibit different levels of awareness.
So, a virtue, an absolute moral would appear to be to separate sex from other activities, as St. Paul promoted.
Parallel this to prohibition--it is logical to outlaw that which causes problems, and alcoholism is huge. Nobody needs alcohol in order to survive. Now we see this logic of perfection leaves us into being a perfect animal. We no longer make choices, but follow perfect paths.
People who promote perfect sexuality, generally admit that nobody is perfect, but apparently sex is the one area where we should be perfect. It is considered that imperfect sex (sex for not creating a baby within a family) is always detrimental, and is implied as the most harmful element to us living together.
This may or may not be, the answers have not been found in the present and are merely conceptual, but it is learned that middle ground is where conflict settles. There will be no perfect sexuality, there will be no absolute imperfect sexuality. It will eventually get closer to middle ground, and that's the way it is.