The phrase "curling one's lip" is often used to describe a facial expression of disdain or disgust. Antonyms for this phrase could include "smiling warmly," "showing appreciation," and "expressing interest." These expressions convey positive emotions and reactions, the opposite of curling one's lip. Other antonyms could be "keeping a neutral expression," "maintaining composure," and "remaining unreactive." These antonyms can be useful in communication and social situations where it is important to convey a positive or neutral reaction. By understanding and using antonyms for negative expressions, we can better communicate and build positive relationships.