Equus
Starring Richard Burton
with Peter Firth and Jenny Agutter, and a horse
Directed by Sydney Lumet from a Play by Peter Schaeffer
1977
I believe in the future historians will have a field day with this film as an expose of the ethos of the era. Today, those perspectives are a bit droll, especially at the begining. The movie does still engage, and builds from there..
I'd put it in a class with 'Last Tango in Paris' for its frankness. This story is about a young man making his way into the sexual world. Richard Burton plays his psychiatrist and is not totally out of the Story. Like Brando in Tango he may well be ending his sexual life.
The movie does contain full frontal nudity, male and female.