Luke is engaging in procrastination, which is the practice of delaying or postponing tasks or actions. It can be seen as a form of avoidance behavior, where an individual chooses to procrastinate instead of taking immediate action. Procrastination can be a result of various factors, such as feeling overwhelmed, lacking motivation, or finding the task unpleasant. In this case, Luke is continuously putting off doing his homework, indicating that he is engaging in procrastination.