The phrase "muscling in" refers to forcefully inserting oneself into a situation or conversation where one is not wanted or invited. The antonyms for "muscling in" would be words that express polite behavior or respecting boundaries, such as waiting for an invitation, asking permission or refraining from imposing oneself. These antonyms could include phrases like "waiting patiently," "asking for permission," "yielding," "respecting boundaries," or "being considerate of others." Choosing to use these antonyms in place of "muscling in" can help to promote good manners, respect for others' opinions, and social etiquette.