Netslave, seriously, don't be obtuse -- you look foolish for fighting this point.
I grew up going to religious schools. In our sex ed and health classes, the "lock and key" metaphor for vaginal sex was used quite frequently. Not only is it a logical metaphor, it is rather ubiquitous.
And I had a few quite fulfilling relationships before marriage that were not chaste (to varying degrees). They were good relationships. I am glad that I had them. These were not "loose" women, we were not being promiscuous. We were sharing meaningful physical contact as part of a meaningful relationship. Yes, I had some relationships that were not nearly so meaningful, but they were the exception, even for me.
If I find out that my 20 year old daughter is having a physical relationship with her serious, longtime boyfriend, and they are being careful and not sleeping around, then again, I won't be THRILLED, but I won't be upset either.
I don't want my daughter to have hangups about sex. When she finally enters into a lifetime partnership with a man, I want her to be able to enjoy sex and participate fully, enthusiastically, and with no limits. Liberated sex is an incredibly important part of a healthy marriage. Too many women come into marriage hampered by the notion (drilled into their heads) that sex is dirty, or their cooter isn't something they should give up. It is almost impossible, logically and emotionally, to go from "nobody should touch my cooter at all" to "let's get freaky" overnight, which is what the total chastity till marriage ethos would have women do. Women can't make that transition -- sometimes, they can't EVER make it. I think that is behind quite a few of the sexually unfulfilling marriages we all see and know about.
I want my daughter to have great, screaming, tear-all-the-sheets-off-the-bed sex when the time comes (yeah, I know -- I will never type that again). I want that because it will make her happy, and will help her have a happy and fulfilling relationship. Pushing ideas of sexual repression and putting MY reputation in the bucket of HER responsibilities is not going to get her there.
I look at it this way -- I think my wife is fantastic. She is an amazingly good and decent woman. I also want her to be a hellcat in the sack. I want her to be completely uninhibited when we're together. That ends up making both of us very happy, and helps keep our marriage happy and healthy.
I would be a lousy father if I didn't want the same for my daughter and her husband someday. I don't think that walking into marriage with a "locked" cooter is a good start. I think it inevitably is oppressive, leads to hangups and anxieties, and ends up being something that must be overcome.
Hell, we all know that women don't go from zero to 60 even in a sesion of bedroom fun, so we also know that they sure as hell aren't going to go from "ultra-pure" to "wow, my wife can really cut loose in the sack" overnight -- or over a year, or over 5 years.
All things in moderation. The Oracle at Delphi wasn't full of ****.
Sex is an incredible and wonderful part of life. It is an ESSENTIAL part of a happy marriage.