A sexual script is basically the behavioral and functional expectations that are imposed on gender roles by their society or culture. For instance, in Western culture men have traditionally been expected to be physically and emotionally dominant along with being competitive. They are expected to display intelligence, competence, and to possess great mechanical abilities.
Likewise, traditionally women in this culture have been expected to be behaviorally and emotionally passive and non-confrontational. They are also expected to be less likely to display their intelligence and are by nature nurturing. Sexual scripts can change over time along with the shifting of the culture at large.