Author ORCID Identifier

Date Available


Year of Publication


Degree Name

Master of Science (MS)

Document Type

Master's Thesis




Kinesiology and Health Promotion

First Advisor

Dr. Kristen Mark


Infidelity is a common behavior, influencing many people within romantic relationships (Mark & Haus, 2019). Many factors have been linked to increased infidelity engagement, but no studies exist documenting the role of sexual fantasy regarding infidelity. One such predictor of infidelity is need fulfillment, or the extent to which one’s needs are fulfilled in their relationship (Le & Agnew, 2001). Sexual fantasy is a highly common, but largely understudied sexual behavior (Lehmiller, 2018). Therefore, the aims of the current study were: 1) to document the role that sexual fantasy and need fulfillment play in infidelity, 2) to determine any potential gender differences in sexual fantasy themes and 3) to determine whether any particular type of sexual fantasy predicted infidelity. Thus, 1,062 adults in romantic relationships were recruited through a combination of social media (n = 265) and the social networking site Ashley Madison® (n = 797) to take part in an online survey. Participants provided their demographics and completed the Wilson Sexual Fantasy Questionnaire (SFQ; Wilson, 2010), the Infidelity Intentions scale (Jones et al., 2010), and a Needs-Fulfillment Measure (Le & Agnew, 2001). An independent samples t-test indicated significant gender differences in type of fantasy such that women fantasized more so than did men about sadomasochistic fantasies, but men fantasized more than did women about intimate, exploratory, and impersonal sexual fantasies. Hierarchical multivariate regression indicated lower levels of need fulfillment to be predictive of higher levels of infidelity intentions among women and men, and higher frequency of sexual fantasy to be predictive of higher levels of infidelity intentions among men. Multivariate logistic regression analyses indicated exploratory fantasy to be the most salient predictor of infidelity engagement, but was only significant among women, such that women who fantasized more frequently about exploratory fantasies were less likely to engage in physical infidelity. The findings of this study contribute to what is known about sexual fantasy and indicate that it may have a more salient role in infidelity intentions and engagement than previously thought.

Digital Object Identifier (DOI)

Funding Information

University of Kentucky Graduate Student Congress Research Award, 2019-2020