Taboo American Style 2: The Story Continues (1985)

This film, together with its prequel and two sequels, is the best adult movie I've ever watched. Part 2 is my personal favorite. It actually has a plot, and the erotic sequences are credible within the context of the film. This is not just a lot of people having sex.

In addition, it features some of the best acting ever in an erotically-oriented movie. Raven, in particular, is devastatingly effective in her role. Taija Rae, too, is very emotionally convincing, although Gloria Leonard seems unsure what effect she is trying to achieve.

Erotically, this film pushes all kinds of buttons beyond just the obvious (incest) theme. The set-ups for the sex scenes includes real build-ups of erotic tension, which makes all the difference when the actual sex happens. Definitely worth your while if you like something more than just disconnected sex scenes (though the sex sizzles as well).