Results from some of my first inquiries into homosexuality in ancient Greece:
[ame=http://en.wikipedia.org/wiki/Homosexuality_in_ancient_Greece]Homosexuality in ancient Greece - Wikipedia, the free encyclopedia[/ame]
Some scholars, such as Kenneth Dover and David Halperin, claim that it was highly polarized into "active" and "passive" partners, penetrator and penetrated, an active/passive polarization held to be associated with dominant and submissive social roles: the active (penetrative) role was associated with masculinity, higher social status, and adulthood, while the passive role was associated with femininity, lower social status, and youth. In this view, any sexual activities in which a male penetrated a social inferior was regarded as normal; "social inferiors" could include women, male youths, foreigners, prostitutes, or slaves; and being penetrated, especially by a social inferior, was considered potentially shameful.
Other scholars, however, argue that male-male relations usually involved an adult male and a youth: the older male took the active (penetrative) role. They also describe them as "warm," "loving," and "affectionate,"  and argue that the Greek tradition of same-sex relations was central to "Greek history and warfare, politics, art, literature and learning, in short to the Greek miracle."
The most common form of same-sex relationships between males in Greece was "paiderastia" meaning "boy love". It was a relationship between an older male and an adolescent youth
I would note that paiderastia ("boy love") is not the same word as arsenokoites. One wonders if scripture meant paiderastia why didn't is say paiderastia.
Given the importance in Greek society of cultivating the masculinity of the adult male and the perceived feminizing effect of being the passive partner, relations between adult men of comparable social status were considered highly problematic, and usually associated with social stigma. However, examples of such couples are occasionally found in the historical record.
 Achilles and Patroclus
Main article: Achilles and Patroclus
Achilles and PatroclusThe first recorded appearance of a deep emotional bond between adult men in ancient Greek culture was in the Iliad (800 BC). Although Homer does not explicitly depict the relationship between Achilles and Patroclus as sexual, by the beginning of the Classical era (480 BC) the two heroes were interpreted as pederastic icons. Since the ancient Greeks were uncomfortable with any perception of Patroclus and Achilles as adult equals, they tried to establish a clear age difference between the two. There was disagreement on whom to make the erastes and whom the eromenos, since the Homeric tradition made Patroclus out to be older but Achilles dominant. Other ancients held that Achilles and Patroclus were simply close friends.
Aeschylus in the tragedy Myrmidons made Achilles the protector since he had avenged his love’s death even though the gods told him it would cost his own life. However Phaedrus asserts that Homer emphasized the beauty of Achilles which would qualify him, not Patroclus, as “eromenos”.
 Historical adult male couples
Among the historical male couples, where both partners were adults, are Euripides, in his seventies, and Agathon, already in his forties. The legendary love between Alexander the Great and his childhood friend, Hephaistion is sometimes regarded as being of the same order.
So it would seem that while pederasty was most common, adult male relations were far from unheard of.
The Sacred Band of Thebes, a separate military unit reserved only for men and their beloved youths, is usually considered as the prime example of how the ancient Greeks used love between soldiers in a troop to boost their fighting spirit. The Thebans attributed to the Sacred Band the power of Thebes for the generation before its fall to Philip II of Macedon, who was so impressed with their bravery during battle, he erected a monument that still stands today on their gravesite
The "youths" spoken of here were apparently of age to serve in the military, and therefore almost certainly past puberty. This would seem to argue that it was not pederasty in the modern sense so much as the higher/lower status issue some scholars assert.
This view now seems outdated. Not all Athenian women have been passive and not all men were dominant. Prostitution, which was an important aspect of Athenian life, had little to do with male dominance; nor was -and this is important- Greek homosexuality restricted to pederastry between a dominant adult and a shy boy.
Meanwhile, however, this image of "pedagogical pederasty" has been challenged by a series of important publications like Charles Hupperts' thesis Eros Dikaios (2000). It is now clear that homosexuality was not restricted to pederasty, and that we have to study our evidence more carefully.
For example, not every older erastes had a beard, and it turns out to be a modern fairy tale that the younger eromenos was never aroused. From literary sources, we know that boys had their own sexual feelings. The sixth-century Athenian poet Theognis, for example, complains about his lover's fickleness and promiscuity. Several vases show young men with an erect penis. Even when he pretends to shy away, he does not protest and does not obstruct his lover's attempt to court him.
Another objection to the traditional reconstruction of Athenian homosexuality is that there is simply no evidence that the presents shown on vases had any pedagogic or didactic value. They are just meant to seduce.
It also appears that the difference in age did not really matter. Not youth, but beauty was important. (The ancient ideal of male beauty: broad shoulders, large chest, muscles, a wasp's waist, protruding buttocks, big thighs, long calfs. A man's forehead was not supposed to be too high, the nose had to be straight, and he had to have a projecting lower lip, a round chin, hawk eyes, and hair like a lion. His genitals had to be small; men with big penises looked like monkeys.)
There are many pictures of boys courting boys, boys playing sexual games, and adult men having intercourse. Yet, the latter was probably unusual or not spoken about, because the passive partner (pathikos) was -as we have already seen- subject to ridicule.
It is not true that homosexual love for boys was an aristocratic phenomenon. The reportory of vase paintings does not change when, in 507 BCE, democracy was introduced in Athens. On the contrary, there appears to be an increase of pederastic and other homosexual representations.
Vase showing male lovers,having sex in public. (Musei Vaticani; ©!!!)
Yet, a decent citizen was supposed not to sell his body, and in c.450 BCE, when the Athenian economy had become fully monetarized, a law was proposed that people who had once prostituted themselves could not run for an office. Someone who had once sold himself was believed to be capable of selling the interests of the community as well. From now on, we find no vase paintings on which the erastes offers money to an eromenos anymore, which shows that these paintings are more or less realistic representations of what actually happened.
Later, this law was no longer applied. In the fourth century, it was not uncommon when two grown-up men shared a home. There must have been jokes about these men, but obviously, they found this an acceptable prize to pay for living with their beloved one. There was a large discrepancy between the official morals, which were expressed in the ancient laws, and everyday life.
Plato (Musei Capitolini, Roma) Plato
As we have seen, the traditional image of pedagogical pederasty is simply mistaken, so what is its origin? The answer is the philosophy of the Athenian Plato. He has painted a very remarkable picture of his teacher Socrates, who is shown -in Plato's own words- as boy crazy. When Socrates was in the company of beautiful boys, he lost his senses. Some sort of mania (divine madness) took possession of him and he was almost unable to resist it. He often complained about the fact that he was helpless towards adolescents, and said that he could only cope with the situation by asking difficult questions to these beautiful boys and teaching them philosophy. So, according to Plato, Socrates sublimated his passion.
Xenophon (Prado, Madrid; ©!!!)
There would seem to be more than a little debate on this matter, and little consensus that Greek homosexuality was limited to pederasty. I will examine the matter further, but so far your assertion appears questionable.
PS: while I'm not Catholic, this page has some good explanations of scriptural support and the church's attitude. Homosexual Practices and the Bible