I recently had a student who consistently and vocally stated "that's not the way Mr. X does it". I sent out an email to the class after a particularly challenging session letting students know every instructor has their approach, particularly with different coursework, and that everyone is expected to behave in a respectful manner. It helped, but I also discovered Mr. X was talking to students about my methods in his class. I brought the issue to my manager and I later discussed it with Mr. X, but really am frustrated he actively undermined my relationship with students. Anyone else had this problem? If so, how did you handle it?