Question

According to the work schedule, it is time for you to take your lunch break. Before leaving, you make sure another coworker in the department is going to cover your area while you are gone. Instead, he tells you that he is also going to lunch. You know he is not scheduled for lunch until later. What would you do?

Answer 1

You tell him politely to go and check his timetable/schedule

Answer 2

You could tell him that you actually think that you are scheduled for lunch, and then he could go and check his schedule. You would have to be nice about it though. If it comes down to it, you could tell your manager or supervisor (but that's not a very good option, just in extreme cases if he's not listening or whatever and it becomes a problem)