Tear through the Old and New Testament. Paul's sermon to the Church of Corinth (Corinthians I or II; can't remember) discusses (in a totally confusing fashion) same-sex relations and of course Genesis, LONG before the time of Jesus, mentions homosexuals as well, or at least was is interpreted as the act of it.
Nobody is saying that it didn't exist back then, not even the Bible...
Even Greek and Roman culture was familiar with same-sex relations. In Greek times, if you competed in a wrestling event and lost you became the winner's slave for a day. This is way way way BC.
