Totally agree that the class element is irrelevant. Where I was doing my undergraduate degree (only graduated last year), it was the 'posh' rugby boys who were the worst exponents of horrible, hideous sexism. Rape jokes, objectification, braying at women, etc etc etc. The uni has two unions and the rugby types all join one in particular- so in the end, by avoiding that union you avoid the worst of it- but then, why should we have had to? When I was there under duress for functions I always felt really unsafe. Its reputation carries and their sexism is challenged- mainly by the so called ' leftie plebs' in the other union,but challenged nevertheless.
I was in a languages faculty and there were relatively few boys/men, and the ones there were were generally lovely- perhaps because most of the women ranged from casually feminist to fiercely militant. There was one guy who had really hideous attitudes to women-he had various ishoooos with being 'rejected by sluts' etc but we all told him, continuously, that he was a twat,and no girl in the department ever touched him with a bargepole. A relatively unsexist faculty environment doesn't override the university-wide sexism though. Sometimes it made life really unpleasant. Unsure what can realistically be done about it though. :(