The phrase "make an exhibition of yourself" means to behave in an embarrassing or humiliating way that attracts negative attention. There are several synonyms for this expression, including making a spectacle of yourself, showing off, being ostentatious, and acting up. Each of these phrases refers to engaging in some kind of behavior that draws attention to oneself in a negative way. Sometimes people make an exhibition of themselves unintentionally, while other times they do it on purpose to try to impress or entertain others. No matter the reason, it's always best to avoid this kind of behavior to maintain a positive reputation and avoid embarrassment.