Interesting excerpt from Albert A Bell Jr's A Guide to the New Testament World published in 1994:
In modern discussions of moral standards, a popular argument is that, when it comes to sex, nothing is “abnormal” or “deviant.” Whatever consenting adults wish to do with or to one another is acceptable. Such an attitude is certainly not biblical. The OT sets out specific rules, governing even some of the more exotic varieties of sexual behavior (as in Lev. 20:10-16; Deut. 22:5), and Jesus raised the standards even higher when he said that whoever thinks of doing such things is as guilty as if having done them (Matt. 5:27-28).
Lacking this religious base for moral decisions, the Romans could justify virtually anything they wanted to do, for the novelty of it if for no other reason. On the basis of what we’ve seen thus far of their behavior, Paul’s description of Roman morals doesn’t seem too far off the mark:
Their women exchanged natural intercourse for unnatural, and in the same way also the men, giving up natural intercourse with women, were consumed with passion for one another. . . . They were filled with every kind of wickedness, evil, covetousness, malice. Full of envy, murder, strife, deceit, craftiness, they are gossips, slanderers, God-haters, insolent, haughty, boastful, inventors of evil, rebellious toward parents, foolish, faithless, heartless, ruthless. (Rom. 1:26-31)
The “unnatural” relations which Paul denounces were obviously homosexual, a form of personal interaction with which the church historically has never been comfortable. The Greeks had exalted male homosexuality as the most meaningful form of personal relationship because women were too uneducated to form an intellectual bond with a man. On the other hand, some women, left to themselves at home and denied any active participation in Greek society, resorted to lesbianism as an outlet for their emotions. The writings of the poetess Sappho (ca. 600 B.C.), praising the beauty of the female students in her school, became popular among some groups of women.
By the time the Romans began imitating Greek culture in the second century B.C., homosexuality had been an accepted part of Hellenic life for centuries. The elite brigade of the Spartan army was the “Lovers,” men who were required to join in pairs on the theory that no man would turn in battle and disgrace himself in front of his lover. Thebes had a similar corps. The Athenian tyrants Hipparchus had been murdered by two men with whom he was involved in a romantic triangle. His murderers became national heroes. Sophocles, Socrates, and other leading intellectuals of Greece had male lovers even when they were quite elderly.
The Romans began to engage in homosexuality as something of a fad, but they were never as comfortable with the practice as the Greeks were. Even though it remained slightly scandalous behavior, it was widely, if less openly, practiced among both sexes by the Romans. Juvenal’s bitter second satire is devoted entirely to a denunciation of male homosexuals. Martial and other sources make it clear that women also took lovers from their own gender.
Imperial leadership was sometimes an incentive to homosexual behavior. Nero engaged in numerous liaisons with persons of both genders. The emperor Hadrian, though married, preferred the company of his male love Antinous, whose untimely death he commemorated in a poem. Those who sought to advance their own careers by flattering the emperor were more likely to adapt their moral to his.
It is clear for the artwork in Pompeii and from literary references that the Romans regularly engaged in sexual activities generally considered immoral in our day. Writers like Petronius and Martial are quite explicit in describing the sexual proclivities of their times, and we cannot entirely dismiss their accounts as mere literary conventions. Sexual aggression plays a large part in Roman humor. What is lacking is a sense of shame. These are merely diversions for a jaded and amoral society, one which differed fundamentally from ours in its attitude toward sexuality.
This is the society to which the early church had to proclaim the teachings of Jesus. How strange his words must have sounded: “You have heard that it was said, ‘You shall not commit adultery.’ But I say to you that everyone who looks at a woman with lust has already committed adultery with her in his heart” (Matt. 5:27-28). Paul’s description of the “degrading passions” and “every kind of wickedness” among the Romans hits right at the mark once we see from their own records what they were like in this era. (242-44)