The phrase "twisted one's arm" is an idiom that is used to describe an act of persuasion, coercion or influence on someone. The antonyms for this phrase could be "let someone decide freely", "give someone the option to choose", or simply just "leave them to it." All these antonyms suggest a non-interventionist approach, where the person has the freedom to make their own decisions without feeling pressured. Thus, when we use these antonyms, it is a way to communicate respect for others' autonomy and their right to make choices independently. Instead of manipulating or twisting someone's arm, we show understanding and consideration for their personal preferences and opinions.