What I need to know is, what terms might such a character use to illustrate that he is talking specifically about sexual intercourse? Would the word 'sex' be mentioned? What euphemisms might he employ?
It would also be useful to know just how much sex was discussed in those days. I've read some literature and watched several films from that era, but what I've read and seen seem to imply that no-one ever talked about it, there was no sex before marriage, and everyone slept in a single bed. What was the reality? Would two gentlemen friends, for example, talk at all to each other about their experiences - or would that be considered completely inappropriate?
If you have information on the subject of homosexuality, that would be great too, though I think that subject has been covered already.
I've searched Google for '1930s British slang sex', '1930s British euphemisms sex', '1930s British synonyms sex', '1930s British slang intercourse', '1930s British slang making love'
Sites offering examples of some 1930s American slang terms, and sites explaining current British slang, but nothing detailing 1930s British slang. Wikisaurus was helpful in producing some examples of what I think I'm looking for, but it didn't tell me whether the phrases were likely to be used by an upperclass Englishman from the 30s or not.