If you watch sex with your offspring then they might ask questions. Violence in my opinion is a lot easier to explain.

violence, it's a lot cooler and less uncomfortable to watch with your kids.

I say violence because it either teaches the child something like, 'this is cool only on tv, but not in reality or; this is the type of stuff going on in the REAL world.' Of course, if you teach/tell your child this stuff. There have been studies done too and there was never conclusive evidence that by watching or playing violence would make the child more likely to be violent. Growing up in a violent life or having violent people around you all the time, is more likley to cause violent behavior.

Now, with sexuality, first, penis's are hardly EVER on TV. They're only recently coming out, but hardly will you see a penis over a breast or a butt. Second, watching something sexual will actually trigger arousal in the child. And that's more likely to be at least the beginning of their sexual curiosity, which could lead to trying to get into a girls pants earlier than they should be trying. Same with a girl becoming more..i dunno, "easy" through curiosity and thinking it's cool.