Madame de Pompadour, the mistress of King Louis XV of France. circa 1750 A mistress is a man's long term female sexual partner and companion who is not married to him. The relationship is generally stable and at least semi-permanent; however, the couple do not live together openly. Also, the relationship is usually but not always secret. There were many men in the past who have kept mistresses along with their wives. Historically, the term has denoted a kept woman, who was maintained in a comfortable (or even lavish) lifestyle by a wealthy man so that she will be available for his sexual pleasure. Such a woman could move between the roles of a mistress and a courtesan depending on her situation and environment. Today however, the word mistress is used primarily to refer to the female companion of a man who is married to another woman; in the case of an unmarried man it is usual to speak of a "girlfriend" or "partner." Historically a man "kept" a mistress. As the term implies, he was responsible for her debts and provided for her in much the same way as he did his wife. In more recent and emancipated times, it is more likely that the mistress has a job of her own, and is less, if at all, financially dependent on the man. A mistress is not a prostitute. Both professions exchange sex for money, but the principal difference is that a mistress keeps herself exclusively reserved for one man, in much the same way as a wife. There is also usually an emotional and possibly social relationship between a man and his mistress, whereas with a prostitute it is solely sexual.