Nonsense.
You are stuck in the rudimentary biological only evolutionary thinking.
Human's are on a whole different path, as much of our evolution over the past few thousands of years is a mental evolution, and not a biological evolution.
Comparing animals to humans at this point is silly, because humans have learned to use their mind to create tools to cook food, have air conditioning, indoor plumbing, computers, watch TV, weapons of mass destruction and nukes, and a variety of other behaviors that are not "natural."
This evolution of man has little to do with evolution of the species, it has to do with evolution of the human mind. Man's biology has not change much in 3,000 years or more. We see no new species of man in thousands and thousands of years.
Modern medicine is not a product of biological evolution. Mathematics and physics are not products of biological evolution, philosophy and art are not products of biological evolution and survival of the fittest.
So as a consequence of this development of the mind, man has been able to escape the jungle and the primitive survival issues. Man need not mate in order for the species to survived. It can now be done in a lab with surrogate partners. Women don't need to breast feed, they can hire a wet nurse or buy formula.
The ways in which we have "evolved" away from animals who are stuck in the primitive animal cycle are immeasurable.
We have a mind that can chose to resist the basic animal instinct, and we can chose to act in any way we see fit. We can be kind and compassionate, we can forgive our trespassers, we can life a life free from the fear of survival that drives the animal kingdom.
So your thinking that gay sex is not "natural" or along the path of evolution and natural selection because it doesn't end in procreation is bunk.
We have no criteria for what is actually natural behavior for human beings, unless acting like a monkey, or a fish, or a cow, or a bird is considered natural...
We are free to decide what to do...
We are not bound by animal instincts for survival...
Quote from volente_00:
Being gay does not fit into evolution and natural selection.