This is always a thorny issue – often filled with emotion and a highly developed sense of right and wrong.

It should not be – it is normal for children between the ages of 4-6 to discover their bodies, and even to discover that bodies have pleasure places.  It never occurs to the child who indulges in immature sex play that he is doing something wrong and the idea that this is forbidden can be confusing and destructive. 

How you react to your child’s natural exploration can shape her body image.  If you yell, look shocked or smack, the message is that there is something wrong with her body.  If you punish or show disapproval, feelings of embarrassment, guilt and shame can become attached to that body image and to feelings of self-worth.  Subsequently, as an adolescent, your child will feel uncomfortable and reticent in discussing questions, problems and doubts about sexuality.  And do you want this to happen?

So, use the approach that bodies are a private, personal matter.  And if your child wants to touch himself, he should do it in the privacy of his bedroom and not in any public place.  Say that in a non-critical, brief manner: “You can rub yourself if you want to but you have to go to your own room first.”
If two children are involved in what is sometimes called “Doctor, Doctor-Play”, divert their attention and mention that what they are doing is not allowed.  Also, do so factually and non-emotionally. 

In extreme cases, if this play persists, it should be investigated further, in case of abuse.  Getting an impartial outsider, like a teacher, to ask tricky questions, is helpful in such situations. However, questioning must be extremely circumspect as prompting or directing answers could compromise investigations and legal action.

As for telling your child about the “birds and the bees”?  Early is better rather than later but responding to questions is usually the best approach.  And don’t share too much information.  Make it age-appropriate, you need not go into great biological detail.  Where things are, their correct anatomical names, what is a good touch and what is bad and that babies are made cos Mummies and Daddies love each other, that’s enough.

So, allow your child to peep under the fig leaf – and CHILL!