Conclusion
Everyone knows that sex and fear are intertwined.
Danger gets the juices of the body flowing and the fear of being caught in the sex act is a natural turn-on that relates to guilt about sex, a logical outgrowth from Brenda's having been caught exposing herself at the age of twelve.
But while everyone would enjoy fucking in an exotic setting, most sensible people are more concerned about potential prosecution and avoid these dangers. Brenda and Joe are not as sensible.
While I have to teach most of my patients to enjoy sexual variety, in this instance this girl must learn to enjoy sexual normalcy.