Space God doesn't want you to have sex outside of marriage. If you're really deep in the abyss, sex is only for procreation purposes, and you have a fly in your Magic Underwear for making babies ONLY. Never enjoy it, because that is SIN!!
The places with the highest rates of illegitimate births are those where SexEd is NOT taught and kids figure it out themselves. So, in van's house (no kids, right?), they aren't going to tell van Jr. about the birds and the bees because that's dirty and sinful. So, little van, not knowing anything (surprise!) goes out and knocks-up his gal pal Shawanda because she's told him she can't get pregnant on rainy days.
This is why we need SexEd. Take religion out of it, please.