This one really IS BL-themed... but not explicitly so.

THE GO-BETWEEN (1970): The Go-Between is a novel by L. P. Hartley (1895–1972), published in London in 1953. The novel begins with the line "The past is a foreign country: they do things differently there." Playwright Harold Pinter adapted the novel into a screenplay of a film of the same name (1970), directed by Joseph Losey; it was Pinter's third collaboration with Losey. The cast includes Julie Christie as Marian Maudsley, Alan Bates as Ted Burgess, Margaret Leighton as Mrs Maudsley, Dominic Guard as the younger Leo, Michael Redgrave as the older Leo and Edward Fox as Trimingham.

http://www.imdb.com/title/tt0067144/
http://www.youtube.com/watch?v=7BD1rAzJgzI (opening scene)


I first read the novel when I was 13, and it took me many years to realise why the book had such a strong effect on me. It involves a young boy who goes to visit a school friend at a Norfolk country house during the summer vacation in the year 1900. In the seeming innocence of the pre-War English countryside, he finds himself drawn into a web of secrecy and desire... but the desires at work are much darker and more tortured than the plot ever openly acknowledges. This is quite appropriate, given that L.P. Hartley, the author of the novel, was what we might describe as a repressed boylover. Pinter's screenplay is recognised as a classic, full of late-60s Freudian angst. It's great.