You cannot file a grievance against a coworker, even if the coworker is harassing or discriminating against you, although there may be recourse outside of the contract and grievance procedure. However, you should follow the University System’s process for dealing with unprofessional,  or bullying behavior. If you believe that your coworker is harassing you or discriminating against you because of race, color, marital status, religion, sex, national origin, age, disability, sexual orientation, or any other protected class under State or Federal Law, or due to sexual orientation, you should notify your supervisor, as well as your steward.  If management does not address the situation, you may be able to file a grievance against management for not dealing with the situation.