Potential influences from using sexually explicit Internet material (SEIM) are controversial, however, the underlying psychological mechanism(s), which potentially can explain these found associations with SEIM consumption, have not been well studied. In the present research, I examine the relationship between SEIM consumption and subjective wellbeing (i.e., sexual and general wellbeing). In particular, I address the circumstances under which the consumption of SEIM is negative for wellbeing by assessing an ideal-actual sexual discrepancy in the context of intimate relationships. I drew on perspectives from self-discrepancy theory to explore whether SEIM consumption generates disparities between ideal and actual sexual experiences, which then may influence consumers’ sexual and general wellbeing. I expected this hypothesized ideal-actual sexual discrepancy to function as one of many underlying psychological mechanisms to explain SEIM’s negative impacts on various types of subjective sexual wellbeing (SSW). I also expected that via SSW, the discrepancy would also explain the ambiguous relationships between SEIM consumption and subjective general wellbeing (SGW) found in the past. That is, I predicted a serial mediation model with sexual self-discrepancy mediating the relationship between SEIM consumption and SSW, and SSW mediating the relationship between sexual self-discrepancy and SGW. Two studies together demonstrated the general progress from consuming SEIM to the evaluation of self-perceived wellbeing under the condition of evaluating sexual experiences with intimate partner(s). In Study 1, the data-driven gender specific sexual preference highlighted the need of model testing separately for men and women because of the potential difference in experiencing the negative impacts from consuming SEIM through the different progress of formation of ideal sex scripts influence by pornographic sex, and generation of an I-A sexual discrepancy in men and women. Results of Study 2 from male SEIM consumers further supported the hypothesized mediation role of I-A sexual discrepancy and SSW (i.e., sexual esteem and sexual satisfaction) in understanding the relationships between SEIM consumption and wellbeing. Overall, the present research illustrated the consumption of SEIM can shape one’s sexual preferences of pornographic sex and generate unrealistic expectations of pornographic sexual experiences with intimate partner(s). Hence, the experience of I-A sexual discrepancy from unachievable ideal sex is a key factor in identifying SEIM’s negative impacts on wellbeing. Moreover, parsimonious serial mediation paths through I-A sexual discrepancy and SSW also demonstrated the relationship between SEIM consumption, SSW, and SGW in one model. This finding indicates SSW works as an important indicator of ones’ SGW. The present research provides a theoretical explanation to understand the impact of consuming SEIM on wellbeing and implicates the importance exploring different types of sexual discrepancy associated with SEIM consumption and ways to mitigate the experienced I-A sexual discrepancy in intimate relationships.