However, you can say that when a man and a woman love each other, they like to be close to one another. Tell them that the man's sperm joins the woman's egg and then the baby begins to grow. Most children under the age of 6 will accept this answer. Age-appropriate books on the subject are also helpful. Answer your child's question in a straightforward manner, and you will probably find that she is satisfied with a little information at a time.
Many parents overreact when they witness or hear of such behavior.
Heavy-handed scolding is NOT the way to deal with the situation. Nor should parents feel this is promiscuous behavior or will lead to promiscuity. Often, the presence of a parent is enough to interrupt the play. You may wish to direct your child's attention to another activity without making a lot of fuss. Later, sit down with your child for a talk.