It seems pretty cut and dry to me. From what i've read, the Bible clearly attributes such activity (homosexual activity) to a deviant lifetyle, foreign to that which we were originally designed by God to partake in. I was told in catechesis that homosexuality is a sin just like any other, and should be repented of. Some have a certain tendency/weakness towards such, just like some have a natural tendency towards addictive substances. There is no indication, from the Church fathers, nor from the biblical canon, that would suggest otherwise about the subject. Culture and society, on the other hand, suggests sympathy towards such a lifestyle, but that is not to be our guide on this earth, lest we stray away from narrow path.