Trivia: Actor Christopher Mintz-Plasse was only 17 during the filming of the movie, creating some problems with shooting due to child labor laws. During pre-production, he was not allowed to see certain props or items from the film (such as Seth's phallic drawings), and his sex-scene had to be very carefully monitored and edited, as certain "actions" (such as too much skin, certain types of movements or positions, etc.) would violate the law.
Trivia: Whenever we see any of Seth drawing the phallic pictures in the flashback, the hands we see drawing in closeups are actually the hands of a small-proportioned woman, because child labor laws wouldn't permit the child-actors to see or draw the pictures. The same holds true for the over-the-shoulder closeup of young Becca looking at the picture.