I agree with Mark Steel on this, which can only lead to the logical and reasonable conclusion that sex education should not be influenced by religion :
So we're left with differing methods of approaching sex education. One might be to acknowledge that we get desires, that can be lethal at times, so it's probably for the best if we find ways of managing them safely and respectfully. Or there's the more traditional method, which is more along the lines of "You know those natural feelings you get – well they're unnatural so stop having them."
They might as well teach that God wants everyone to be cold, and if we feel a desire to shut the door in winter we must fight the temptation, and we must go to the park in January in our swimming trunks to and, if we shiver or reach for a coat, that's Satan at work and we should discuss it with the priest.