"Stu...I think you are simply wrong here, I do not accept that animals, with the exception of humans, knowingly have same gender sex.
In the "lower" animal world sex is triggered by instinct and chemical signals between male and female animals.
Two males simply do not have the capacity to make these chemical signals."

This statement indicates you might have a rather naive view of sex and its function. Apart from procreation many species use sex as form of socials bonding, reinforcing relationships within groups and these are the reasons sex occurs between males. There are sound biological reasons for this behaviour, it exists and is studied closely as it gives us insight into our own nature. What you're doing is putting an anthropocentric slant on the behaviour of other species, and this has long been discredited as we begin to comprehend the nature of animal consciousness. They do think like us, although there are parallels (as an aside, I often wonder if the tetrapod way of thinking differs radically from that of a mollusc, such as an octopus? We recognise certain aspects of our own thinking in some animals, but are beginning to realise that many have very different ways of comprehending the world. But then some humans do; I saw a documentary on telly about an isolated forest tribe who had no concept of time as a linear process. They just were. Isn't all so wonderful?)

There is little doubt that we underestimate the intelligence and cultural nature of many animal's societies. We observe tool use in species ranging from us to birds (lotsa wonderful stuff on YouTube, plus the zoology blogs), we know many animals are capable of exchanging complex information on an intra-sepcies level, transmitting information between generations and have advanced problem-solving capabilities: they reason and can think in terms of steps ahead.

So suggesting that any animal is 'lower' is considered ludicrous (except in phylogentic terms, but that's not a judgement) and projecting our own human assumptions onto animals is equally wrong. Homosexuality is a natural variant of animal (including human) behaviour, is certainly not "perverse" (more judgement) and from a biological viewpoint has evolved as an important social mechanism.

Morality is a social construct. It is borne of a consensus amongst a population that certain actions cause harm to the greater good. Religious types will say their particular creed is the one and only correct moral source, some people (like myself) would concluded that many of our most basic moral principles were decided on a long time before the religions we have today were formed, and many of these tenets are fundamental to us all, regardless.

Homosexuality has existed since there were people and it has never dragged a society down. Worrying about what consenting people get up to in their bedrooms is rather sad to my mind, and is a distraction from the real issues facing us. Forcing our views on people whether religious (teaching creationism as science) or cultural (anti-gay, racist) is simply not the way forward for any society, end of.