Extramarital affair

Extramarital affairs are relationships outside of marriage where an illicit romantic or sexual relationship or a romantic friendship or passionate attachment occurs.

An extramarital affair that continues in one form or another for years, even as one of the partners to that affair passes through marriage, divorce and remarriage, could be considered the primary relationship and the marriages secondary to it. This may be serial polygamy or other forms of nonmonogamy.

The ability to pursue serial and clandestine extramarital affairs whilst safeguarding the secrets and conflict of interest inherent in the practice, requires skill in deception and duplicitous negotiation. Even to hide one affair requires a degree of skill or malicious gaslighting. All these behaviours are more usually called lying.

Deception can be defined as the "covert manipulation of perception to alter thoughts, feeling, or beliefs". The presence of deception may indicate the degree to which the deceiver has breached fundamental conditions of fidelity, of reciprocal vulnerability and of transparency. Sometimes these are explicit or assumed pre-conditions of a committed intimate relationships.

Individuals having affairs with married men or women can be prosecuted for adultery in some jurisdictions and can be sued by the jilted spouses in others.As of 2009, eight U.S. states permitted such alienation of affections lawsuits.