Sorry, what's GHD?
I think the conversation is getting more serious than either of us intended. I just don't think that sex is necessary to make a relationship more legitimate and therefore wouldn't be something to make anyone want to rush a marriage. Particularly given that most colleges aren't overly happy about students getting married during their degrees.
Out of interest, do you think that getting married would be much more of a committment (or a detriment to studies) than any other serious relationship? I'm not sure whether colleges are actually opposed to marriage itself or if they just can't offer married couples accommodation. I wish I'd read the matriculation form more carefully now, but unlike Corpus I don't think Sidney actually make you promise not to get married. I wonder how much this differs across colleges.