Antonyms for the phrase "bellies up to" include "backs away from," "shies away from," "avoids," "withdraws," "retreats," and "shuns." These antonyms suggest a lack of engagement, reluctance, or hesitation to approach a situation or interact with others. They could also imply a sense of fear, uncertainty, or discomfort in social or public situations. In contrast, "bellies up to" suggests a bold and confident approach towards socializing or engaging with a situation, indicating a willingness to be open and proactive about personal interactions. Understanding these antonyms can help one express their hesitancy more effectively in conversation or communication.