How pelvic thrusts can affect a film's rating

Somewhere in a brightly lit corporate office, a group of highly paid adults is rigorously counting the exact number of times a hip moves. To differentiate between a mature R-rating and a restrictive adult-only rating, censorship boards actually have unwritten numerical limits on pelvic thrusts during intimate scenes. One thrust too many, and the entire project is deemed a menace to society.