It is often argued that the word "arsenokoites" which occurs in 1 Corinthians 6.9 means "homosexual prostitute" and not merely "homosexual."  Here are two occurrences outside of the Bible which would certainly seem to indicate that the word is referring to homosexuality per se, and not merely prostitution.

Bardesanes of Syria (AD 155-220)

Laws in Hatra. - There is a law in force in Hatra, that whosoever steals any little thing, even though it were worthless as water, shall be stoned.  Among the Cashani, on the contrary, if any one commits such a theft as this, they merely spit in his face. Among the Romans, too, he that commits a small theft is scourged and sent about his business. On the other side of the Euphrates, and as you go eastward, he that is stigmatized as either a thief or a murderer does not much resent it; but, if a man be stigmatized as an homosexual [arsenokoites], he will avenge himself even to the extent of killing his accuser.  ... Again, in all the region of the East, if any persons are thus stigmatized, and are known to be guilty, their own fathers and brothers put them to death; and very often they do not even make known the graves where they are buried.  Such are the laws of the people of the East.  But in the North, and in the country of the Gauls and their neighbors, such youths among them as are handsome the men take as wives, and they even have feasts on the occasion; and it is not considered by them as a disgrace, nor as a reproach, because of the law which prevails among them.

Hippolytus, Bishop of Rome  (c. AD 200)

"Of every tree that is in paradise thou mayest freely eat, but thou mayest not eat of the tree of the knowledge of good and evil," which is Naas.  Naas...has committed sin, for he went in unto Eve, deceiving her, and debauched her; and this is a violation of law. He, however, likewise went in unto Adam, and had unnatural intercourse with him...whence have arisen adultery and sodomy [arsenokoitia].