Have you read Lauren Winner's Real Sex? She addresses these very same topics. I haven't read the whole book yet, so I can't vouch for any conclusions she might make, but it might be worth a look. 

Of particular note are Winner's remarks about the church community's role in "sex ed," a term I hesitate to use because it sounds finite, when instead (as Winner says) it should start at day one and continue into adulthood, even for married folk, getting progressively more detailed and complex. This culture of discussion that seems nonexistent in a religious context.