My DS1, aged four, has recently progressed from toilet talk to some really awful talk about body parts. I won't go into details. I probably sound very prudish. I had a brother close in age so I do realise that boys can be like this, but is four very early? Where do they get this stuff. He isn't allowed watch unsuitable tv. He does go to creche and his dad makes bottom jokes but it seems to be getting a bit far. Anyone else have this problem and how should I handle it.