The problem you have is in how secular sciences view homosexuality.  How do you protect students from the learning the latest research on LGBT, when that research contradicts the underlying premises of Natural Law theory.  Hopefully a Catholic university is graduating students capable of dealing in their chosen professional worlds, and research on gender issues is a part of many disciplines, and that research is grounded in an entirely different approach than that of natural law.  The same thing would hold true in business schools.  Students have to be able to study the currently available information on both economic systems and ethics.  If we want our kids to have professional jobs we have to teach them what's out there in the scientific information highway and not limit them to theological alignments.