Sex in movies is when two people show their bodies and do physical activities together that let them show that they like each other. Sometimes, when the two people really like each other and care about each other, they might actually be having sex. However, most of the time, the people in the movie are just pretending that they are having sex, and they aren't really doing it. Watching how two people show their love for each other and how they touch each other is what movie makers call sex in a movie.