The phrase "upsetting one's apple cart" is typically used to describe a situation where someone's plans or ideas have been disrupted or adversely affected. However, there are certainly times when we want to prevent such a scenario from occurring, and this is where antonyms for the phrase come in handy. Some potential antonyms for "upsetting one's apple cart" include "supporting," "encouraging," "facilitating," "enabling," "assisting," "aiding," "abetting," "promoting," "fostering," and "nurturing." While each of these words may have slightly different shades of meaning, they all suggest an intention to help someone achieve their goals rather than hindering or disrupting them.
