this is my opinion Infidelity is a personal relationship outside of marriage, involving at least one married person, and is based on three elements:
Interests
Interdependence
Match each other emotionally and sexually.
Infidelity does not always mean a relationship involving sexual contact. Although there is no sexual contact, but if there is a sense of mutual interest, mutual dependence and emotional and emotional fulfillment that can already be categorized as an affair.