Dear Christian America, Of Which I Am Still Nominally A Part:
Knock this shit off please.
I'm serious. This is the kind of thing that makes my teeth bleed. Kids get "exposed" to a lot of things that parents can't control. It's better for them to become aware of them in a controlled environment (school, for example) than it is an uncontrolled one (the back of somebody's car).
Reality is an ugly, uncaring, unfeeling, horrible place. Sheltering your kids from it will not work for very long. It likes to get in through the cracks. You can either let your kids know this and arm them to fight the nasty, or you can shelter them and leave them pretty much defenseless against it. I'd rather have sex education than pregnant fourteen year olds. I'd rather have books about rape than students too scared to come forward. I'd rather show my kids everything, all the beauty and all the ugliness, as high as it can get and as low as it can get, in the safe environment of childhood rather than hide the cracked spots and let my kids become disillusioned when reality bites.
Your job as a parent is not only to keep your children pure. It's also to arm them for a life that's little more than a running fight against the dark.