It depends a little on the context. The obvious male counterpart is master. In context like Does Jim have a mistress?there is no exact counterpart, but you could use lover.
In terms of mistress implying that she is in charge of a servant, the counterpart is master. In terms of mistress implying that she sleeps with men other than her husband, the counterpart is gigolo. You might also use the term adulter and adultress.
Mister(mr.)
The masculine form of master is "master." Both masculine and feminine forms of this term are the same.
In English there are no masculine or feminine forms. English uses gender specific nouns for male or female.The noun 'mistress' is a gender specific noun for a female.The corresponding gender specific noun for a male is master.The plural form of the noun 'mistress' is mistresses.The plural form of the noun 'master' is masters.
In English there are no masculine or feminine forms. English uses gender specific nouns for a male or a female.The noun for a male is master.The noun for a female is mistress.
In English there are no masculine or feminine forms. English uses gender specific nouns for a male or a female.The noun for a male is master.The noun for a female is mistress.
A man servant.
In English there are no masculine or feminine forms. English uses gender specific nouns for male or female.The noun for a female manager of a post office is postmistress.The noun for a male manager of a post office is postmaster.
In English there are no masculine or feminine forms. English uses gender specific nouns for male or female.The noun master is a word for a male who is in charge; the noun mistress is a word for a female who is in charge.
The masculine is headmaster.
In English, there are no masculine or feminine forms. English uses gender specific nouns for male or female.The noun for a male is manservant; the noun for a female is maid or maidservant.Although generally the case, there are some masculine/feminine forms eg waiter/waitress, master/mistress, Mr/Mrs, dog/bitch.
In English there are no masculine or feminine forms. English uses gender specific nouns for male or female.The nearest equivalent of the noun 'mistress' as a word for a female in charge or with authority is master. Others are headmaster, captain, commander.The nearest equivalent of the noun 'mistress' as a word for a 'kept' woman is gigolo. Others are paramour, escort, inamorato.
The word mistress, for example, has no male-equivalent. There's no opposite to βthe other woman.β And that influences behavior. People are more likely to blame βthe other womanβ when their husbands cheat. But when a wife cheats, there's no collective blaming of βthe other man.β