"Basing itself on Sacred Scripture, which presents homosexual acts as acts of grave depravity, tradition has always declared that "homosexual acts are intrinsically disordered." They are contrary to the natural law. They close the sexual act to the gift of life. They do not proceed from a genuine affective and sexual complementarity. Under no circumstances can they be approved. 

The number of men and women who have deep-seated homosexual tendencies is not negligible. This inclination, which is objectively disordered, constitutes for most of them a trial." (CCC 2357 - 2358)

This term "disorder" does not refer to the person himself. Catholic teaching is that the homosexual inclination and homosexual acts are directed towards an end not intended by God, mutual complementarity, marriage, and procreation, which lead to man's flourishing and happiness. The sexual attraction between male and female is naturally ordered toward this good; same sex attraction is not.