The bishops fire homosexuals who are in active relationships.  Paragraph 2358 of the CCC says,

"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. They must be accepted with respect, compassion, and sensitivity. Every sign of unjust discrimination in their regard should be avoided."

Obviously, the bishops feel that firing gays is "just discrimination". I would disagree.