I often use marriage as an example of a widespread (philosophical) truth, namely, that just because two people use the same word doesn't mean that they mean the same thing by it. ("Hey, baby, yes, I'm totally committed to you...er, tonight...")
(Parenthetically: Ceylon tea in the morning...ahhhh...now, back to my post:)
Standing at the bus stop this morning, I had a itsy bitsy witsy realization along the marriage lines.
If extramarital sex is for you, or your cultural niche, no big deal, just fine, etc., then surely premarital sex is not going to be a big deal.
But if you're already having sex with someone, and living together, what kind of commitment are you asking of each other when you ask to get married? Although this may not be your intention, it might be that, in terms of your own and / or the other person's frame of reference, you're actually to be understood as asking for a commitment to a
wedding
. No wonder people, resistant to this, often think of it as "only a ceremony."
Of course there are many reasons people engage in (extramarital) sex, and many attitudes to it. And more reasons yet for why people who are married do not engage in (marital, anyway) sex. So I'm not suggesting this covers all or even most cases, only many cases at least in the US (maybe Europe and the British dominions too).
Still, I do think that this one particular dynamic might be even more the case if
1. you're not opposed to, but just have never seen a long-term, til-death-do-us-part relationship, or at least never seen one you thought as relevant to you at all, and / or if
2. having a baby is not associated by you with being married, and / or if
3. you view decisions as choices, and choices as (arbitrary) choices among options, and thus view "continuing to have options" as necessary to "continuing to be a person who is a decision-maker," i.e., a(n arbitrarily) free adult--i.e., if you think of yourself basically as a consumer.
Again, there are a thousand thousand nuances here in particular cases, and far more than one cultural development going on in America simultaneously. One of the problems with talking seriously about issues like this is that with 300+ million people, just about any generalization you might want to make is going to be true, at least among some subset of Americans, and way false of large groups of others. I certainly don't mean to reduce the existential depth of anybody's particular working through issues like this; quite the contrary, my bus stop light bulb came from reflecting on students' attitudes and questions.
Of course I've thought for a long time that the deep misunderstanding of symbols in American culture makes all of this unnecessarily hard for people to get. On the one hand, from the side of 'Does my behavior make me thoughtful about anything?', if sex isn't a meaningful act, because "we all just know" that actions aren't meaningful, then of course you're not going to think there is a connection between it and anything meaningful in one's life. If you do ask about meaning, one common worldly answer might be some fuzzy thing about emotions or a hard one about evolutionary priorities.
On the other hand, from the 'does sex have any meaning and if it does, what?', if vaginal intercourse isn't the symbol of complete commitment, what is? Manual? Oral? Anal? Group? It's a pretty universal view of cultures and religions that whatever else one thinks about sex, whatever else it is and however else one views other sexual behaviors, vaginal intercourse in marriage is somehow the sign or seal of that marriage--not, normally, that intercourse makes you married, but that marriage appropriately calls for intercourse to express its reality in physical form: that it is marriage enacted in a symbol, encapsulating it the way that sharing the dishes and the bills and the vacuuming and so forth are marriage in routine action.
A symbol is a meaning "thrown together--sym-bol" with a word, object, or action. Since we humans are ourselves symbols--meaning-filled bodies--symbolism is at the core of who we are and what we do. I think that's among the best ways to think about sex, and sex ethics.