When Should LGBT Teachers Be Fired?

Catholic school administrators should not fire someone because of the religion he practiced when he was hired. But if teachers are lay ministers of the faith, then yeah, you should hire and fire teachers based on their religious affiliation. Hiring a teacher in a so-called same-sex marriage is not like hiring a Presbyterian. It's like hiring a polygamist. And if a teacher sets a bad example for students, when should they be let go? What moral teachings of the church should a Catholic school teacher exemplify?