Aim and Background: Sexual diversity, as a psychological and social concept, refers to the desire of individuals to experience emotional or sexual relationships outside of the marital framework. The aim of this study was to investigate urban differences in sexual variety-seeking and its dimensions and to explore the psychological, social, and cultural factors associated with this tendency among couples on the verge of divorce.

Methods and Materials: A mixed-methods design was employed. In the quantitative phase, 1,100 couples on the verge of divorce were selected from Tehran, Isfahan, and Gonbad Kavous using Convenience Sampling and assessed with the Sexual Variety-Seeking Questionnaire. Data were analyzed using descriptive statistics, one-way ANOVA, and Tukey’s post-hoc tests. In the qualitative phase, 20 experts in  clinical psychology,  family counseling, and sociology were purposively sampled and interviewed through semi-structured protocols. Thematic analysis was conducted using NVivo software.

Findings: Quantitative results indicated that mean scores of sexual variety-seeking and its subscales were significantly higher in Tehran compared to Isfahan, and in Isfahan compared to Gonbad Kavous (p<0.001). ANOVA confirmed significant differences among the three cities, and Tukey’s test revealed significant pairwise differences. Qualitative results identified five major themes: cultural and normative pressures, socioeconomic difficulties, poor communication skills, personality and psychological factors, and lifestyle changes linked to modernity.