I am going to throw a grenade into this one three sides probably.
1) The federal government's interference in education is unconstitutional. The Constitution does not give the federal government the authority to control or to fund education. Therefore, any action in that area is unconstitutional as the Constitution specifically forbade implied powers in the 10th Amendment.
2) Since sex is a topic that is laden with religious, moral, and legal baggage, it is best left to parents to teach it.
3) However, if it is deemed by the citizens that they want their school to teach a sex-ed topic, the school is obligated to teach it in a factual manner. This means including that abstinence is the only 100% effective method of preventing preganacy and STD's. It should also include methods of safer sex, and what real level of protection they provide.
Parents can add the morality and religion to the material.
Really, though, the more you shove abstinance at kids, the more tempting sex is going to be for them.
