The antonyms for the word "acting up on" are behaving well, obeying, complying, and following regulations. These words all suggest a sense of obedience and conformity, which is the opposite of acting up on. When someone behaves well, they follow the expected code of conduct, whereas acting up on implies a disruption of order or breaking of rules. Obeying and complying suggest that an individual is following the rules, while following regulations suggests that they are adhering to protocol. It is important to recognize both the positive and negative aspects of behavior in order to maintain order and accountability in any given situation.