According to Webster, a mistress is:
4 a : a woman other than his wife with whom a married man has a continuing sexual relationship
I only bring this up because, last night when I was listening to ABC News, they referred to a public figure who was caught cheating on his wife. According to the "news" sources, several dozen mistresses then appeared out of the woodwork.
I just want to know when a one-night stand, a conquest, a notch in the bedpost became known as a mistress. I find it hard to believe that this individual had "continuing" relationships with that many women. Why can't we just use the correct words? These women are not mistresses. They are adulteresses.