Affair

An affair is a relationship typically between two people, one or both of whom are either married or in a long-term relationship with someone else. The affair can be solely sexual or solely physical or solely emotional – or a combination of these. People who involve themselves in affairs do so out of the need for just sex, an intimate relationship, passionate attachment or a combination, which is often referred to as a "soul tie".

Relationships are considered to be contracts. They may be a formal one like marriage – consisting of both a verbal and written contract, or an informal one – consisting of only verbal contract. Because most affairs are clandestine in nature, an affair breaks those contracts. Clandestine affairs can commonly cause feelings of betrayal to the other person in the primary relationship. Ironically, affairs themselves are also contracted relationships and come with numerous stipulations and rules.

An affair is different from a "fling" in that it is usually long-term. The word for the most-likely unmarried partner in an affair is the gender-neutral French "paramour". Affairs are often emotionally lopsided in that paramour will be the only one to heavily invest themselves into the affair.