Affair has the same word origins as affect — an affair implies bonds of affection, but not necessarily so. Some affairs are premeditatively cold, exploitative or designed to extract information or to provide the basis for later blackmail or grounds for divorce.
In the most general sense, affair may be used to connote professional, personal, or public business. These include meetings or other functions, or tasks that need to be completed. For example, one might say, "I have other affairs to attend to at the moment." It may also refer to a particular business or private activity, as in family affair or private affair. An affair, in the political sense, typically refers to any kind of involvement in illicit business by any kind of public representatives, such as in the Watergate affair. Like the earlier definition this is not always the case — for example the British Government has a Secretary of State for Foreign and Commonwealth Affairs, which is a perfectly legitimate (and usually honorable) position.
Affair is not only used to describe cheating but may also describe part of an agreement referred to as open marriage, which sanctions some extramarital affairs and not others. When one of the non-sanctioned affairs occurs it is described as infidelity and often experienced as a betrayal both of trust and integrity.
Affairs are sometimes accompanied by scandal. When used in this context, "affair" usually implies sexual impropriety, but that is not necessarily the case. For example, in the classic film An Affair to Remember, the love affair in question might be considered acceptable from some moral standpoints. However, an emotional affair can be as devastating for the one who is excluded or betrayed by it as if a full sexual liaison had occurred. By contrast the film Dangerous Liaisons shows many sides to a culture of illicit affairs between the main characters. It explores the escalating costs of covert and immoral adventures.
The linkage of sex and romance with affair provides the basis for entertainment in advertising, art, literature, film, plays and in TV soaps. It can fuel crusades against monogamy or promoting the value of monogamy.