The phrase "most twotiming" refers to someone who is dishonest or disloyal in their romantic relationships. Antonyms for this phrase would be terms that describe individuals who are faithful, trustworthy, and reliable partners. An example of an antonym for "most twotiming" would be "committed" or "devoted." These words imply a level of dedication and loyalty to a partner that is completely opposite to the negative connotations of "most twotiming." Other potential antonyms could include "honest," "loyal," "faithful," and "true-blue," all of which describe individuals who prioritize their relationships and are committed to being faithful partners.