The word "mistresses" has a negative connotation as it is often associated with infidelity and adultery. Therefore, it is important to have alternative and less offensive words to describe the same concept. Some synonyms for "mistresses" are paramour, concubine, courtesan, lover, or sweetheart. These words have a more positive and romantic connotation, though some may still have a slightly archaic or formal feel. In modern language, it is more common to use neutral terms such as partner, significant other, or companion to refer to a person with whom one has a non-marital romantic relationship.