Mom Against Abstinence
I think "abstinence until marriage, faithfulness afterward", far from being "the only 100% safe approach", is a proven formula for disaster.
As far as I can tell, "abstinence" in this sense includes never having any orgasm-related contact with another human being before marriage. That is, it encourages ignorance, clumsiness, and lack of knowledge of self and others. For women in particular, this means that they are much more likely to find marital sex unsatisfying, as neither half of the sketch has enough hands-on knowledge of female sexual response to get her where she wants to go. Unsatisfying marital sex is a Bad Thing, not least because it leads to more divorces, a Really Bad Thing.
Abstinence-until-marriage also naturally leads to earlier marriages, as young people get married so they can legitimately have sex. Early marriages lead to more divorces, which, again, a Really Bad Thing.
Abstinence-until-marriage also encourages the mindset in which certain behaviors are labelled "sex" by adults, and so teenagers indulge in other behaviors because they "don't count", but without taking appropriate precautions either medically or emotionally.
For instance, oral sex is a *really* effective contraceptive, but there are still disease risks -- which is why teenagers could stand to learn about flavored condoms -- and it has emotional/relationship risks if it doesn't go both ways, if it just becomes a power trip. Exploitative sex is also a Really Bad Thing.
One of the worst things about "abstinence until marriage, faithfulness afterward" as an educational program is that it is so patently hypocritical. Kids aren't stupid -- they look around at the behavior of the adults they know and the ones depicted in movies, TV, and ads, and they will infallibly conclude that AUMFA is not standard, normal adult behavior. "Do as I say, not as I do" is a Bad Thing, because it leads kids to assume adults are always lying, even when we say "don't mix downers and alcohol" or "don't drive 70 on that twisting road". And those are Really, Really Bad Things.
AUMFA makes adults feel good, but it is a disservice to young people on multiple levels, and I'm against it.