A "discreet" sex would be masturbation in the loneliness of the North Pole.

Discrete sex, on the contrary, is something else. All sex should be discrete, unless in a voyeuristic/exhibitionist club.

And, of course, sex with one's own student is NEVER acceptable. There are millions of people in every Chinese city. One should even refrain from sex from other students at the same school whom one does not teach, but one's own students -- ABSOLUTELY NEVER.

It's difficult to work out what you are meaning- meaning to say- tad disjointed? However, you say "And, of course, sex with one's own student is NEVER acceptable" I'm afraid, to say it's highly acceptable to some posters. Let's make one thing clear, a loving relationship between an adult man and woman, often occurs when sometimes it would be better if it didn't happen- there is nothing morally wrong with it; although I accept that it could be unwise; but it happens, these things happen. We, or I, am not talking about shagging students willy-nilly; or unnatural sex with under-aged ones .

As for your starting sentence, I can't make head or tail of it- it doesn't make any sense to me, although I know what each constituent word means.