When I knew my son was starting to explore his sex parts by playing and masterbating (I have caught him a couple of times in the shower or in the bed), I knew this would be a perfect time to explain to him about the okay's in masterbating and nos to people touching his privates. And every year I add something else to the conversation. He has been involved with girls (playmates) before kindergarten, but I know he is wanting to show his love the same way I show love to my partner, by kissing, holding hands, and hugging, etc. Holding hands are ok, hugging okay, kissing you ask me first. He hates these conversations, but I myself was sexually abused at the age of 9years old by my own father until the age of 12years. So the earlier the better.