Studies suggest around 30–40% of unmarried relationships and 18–20% of marriages see at least one incident of sexual infidelity.Rates of infidelity among women are thought to increase with age.
Differences in sexual infidelity as a function of gender have been commonly reported.Article uses three citation styles: inline footnotes, a "references section" and a "further reading" section. For example, the first citation, Leeker & Carlozzi, points to the further reading section. Infidelity (synonyms include: cheating, adultery (when married), netorare (NTR), being unfaithful, or having an affair) is a violation of a couple's assumed or stated contract regarding emotional and/or sexual exclusivity.The second citation (Weeks) is both defined in text and pointed at using a footnote. Other scholars define infidelity as a violation according to the subjective feeling that one's partner has violated a set of rules or relationship norms; this violation results in feelings of sexual jealousy and rivalry.In general, national surveys conducted in the early 1990s reported that between 15-25% of married Americans reported having extramarital affairs.Treas and Giesen found that people who had stronger sexual interests, more permissive sexual values, lower subjective satisfaction with their partner, weaker network ties to their partner, and greater sexual opportunities were more likely to be unfaithful.In that study which involved 19,065 people during a 15-year period, rates of infidelity among men were found to have risen from 20 to 28%, and rates for women, 5% to 15%.