If it has only been 3 weeks since this behaviour has been discovered then I would continuously monitor the situation although at the same time not fall into a "crisis mode" type attitude about the incidents. Some children at that age experience a brief and temporary curiousity about their "private parts" and as parent it is your responsability to educate rather than "scold" or in any way make your child feel as if he/she is bad or naughty for exploring their bodies. A five year old demonstrating these types of behaviour is a delicate subject and could have long term effects in not handled properly by the parent. I recommend that you seek professional help if you are unsure on how to deal with the situation in the correct manner...
