playing doctor

I dont know what to do. I just caught my 6 year old daughter and niece "playing doctor." I went into the room and my child was in her bed naked. When I asked them what they wwere doing my niece said they were going to kiss their privates. Is this a sexual behavior or are they just exploring? What do I say to them to stop this from happening agian?

[Kevin Kennedy, Ph.D.]

I would be suspicious of this due to the aspect of kissing. That does not spontaneously occur to children. One or the other has been introduced to such a consideration (not necessarily in a direct way). So it's important to try to figure this out. Relative to what to say, it's pretty simple. You tell her that it must stop and not be repeated. This is straightforward limit setting - it does not require any finesse.