"Pushes one buttons" is an idiomatic expression that refers to something that irritates, annoys, or hurts someone deeply or on a personal level. If you're looking for synonyms for this phrase, you might use terms like "pushes one's triggers," "hits a nerve," "strikes a chord," "rubs one the wrong way," "gets under one's skin," "tweaks one's emotions," "sets one off," or "prods one's sensitivities." Each of these phrases conveys a sense of being provoked or agitated on a deep level, and can be used interchangeably to describe the feeling of having one's personal boundaries challenged or threatened.