The antonyms for the phrase "hitting up on" could include terms such as avoiding, ignoring, or neglecting. These words indicate behaviors opposite to approaching or interacting with someone, particularly with romantic intent. Other antonyms may include retreating, withdrawing, or disengaging, all of which imply a distance or separation between two individuals. These antonyms could represent a lack of interest or desire to connect with others, whether it be due to personal reasons or social anxiety. In contrast, "hitting up on" implies an act of courage, confidence, or even assertiveness, demonstrating a willingness to put oneself out there and take risks in interpersonal relationships.