in the scene where O is bent over the settee, is she being buggered?
her face seems to suggest it, but watching the film over the weekend, im not so sure
anyone help?
I would say so, yes. The book spells it out pretty clearly.
Woman is the Earth and Man is the Sky.
The book is very clear that anal penetration is very much a part of her training. The first night she is virtually raped in the "narrower passage" as she is made to scream in pain. Then while tied and being whipped, "the man who liked women only for what they have in commen with men" seduced by the available behind, "spread the burning halves and penetrated, not without difficulty."
As a result of that, the second night begins a series of nights when she is spread and stretched more each night by a larger and larger device.
And, if I understand correctly, Sir Stephan uses only that opening and her mouth, tearing her the first night in spite of the fact that she has been stretched.
The movie, of course, is far less clear -- for several reasons. But the later series of VCR/DVD is more clear about what is happening.