Antonyms for "curling one's lip at" would include phrases such as "smiling warmly at," "showing respect for," and "expressing admiration towards." These antonyms would all convey a positive response, rather than a negative or judgmental one. For example, instead of curling one's lip at someone's outfit or behavior, one could choose to smile warmly at them or show respect for their choices. By using these antonyms, one can shift the tone of the conversation from critical to accepting, and foster a more positive and inclusive environment.