OK these people are fucked up in the head pure and simple. Even dogs try to hide in the bushes when they copulate. To have sex in front of your children as a means of "teaching them" about sex is just about as off the wall as I think you can get to justifying some sort of exhibitionist behavior that I believe to be child abuse as well.
HOWEVER, I find it more horrifyingly disgusting that more parents (the abusers that is) aren't jailed for BEATING THE SHIT OUT OF THEIR PARTNER IN FRONT OF THEIR KIDS.
i guess i'm the only one who doesn't really think this is that bad. if they didn't force her to watch, who cares? she'll be watching scrambled porn on tv soon enough anyway