Definitions:
Infidelity: Unfaithfulness to a primary partner, which can take the form of a sexual and/or emotional extra dyadic involvement with another person.
Jealousy: A reaction to a threat to the relationship, reaction to loss of a partner, or response to a degradation of a relationship’s individual values. This can be triggered by real or potential threats.
Both infidelity and jealousy have been around for centuries. Infidelity is the biggest predictor of divorce. Jealousy can take the form of emotional jealousy or sexual jealousy. Jealousy develops as an adaptive mechanism in both men and women who perceive a threat to their reproductive success, and it motivates behavior aimed at reducing that threat.
