Sexual exposure in movies, songs etc does affect children
I wasn't very old, maybe kindergarden. My sister (4 yrs old) and I snuck into the family room to watch a movie. I can't remember for sure, I think its tommy knockers? Where there is this space ship or whatever in someone's yard that they dig up and the more they uncover the hornier everyone gets. Whatever it is, there's a TON of sex in it. In one sceene a woman is sitting on a bed and takes a man's face and shoves it into her crotch then starts moaning. I was very confused by this... And I wanted to know why she was moaning like that. So that night when I went to bed I started playing with myself to find out why she liked it so much. I was masturbating everyday in elementary school. I was very well aware of what sex was and that touching those parts felt really really good. By the time I was in 6th grade I was having oral sex (and it wasn't poor parenting. Kids are very sneaky and schools aren't as secure as one might think). I lost my virignity when I was 13.
I really believe if I hadn't been exposed to something like that movie at such a young age, I would not have been experimenting sexually so young. Maybe I would have, who knows.
But please just remember, these things DO imprint on our children. Just because you may not think they realize what something is, doesn't mean they won't try to find out.