My 5 year old Son was caught touching another childs privates

I have a 5 year old Son who was caught recently touching another 5 year old girl on her privates. From what i have learn he has done this more than once infact i believe it has been 3-4 times. I also learned it happened with 2 other children he playes with. I have talked to him and explain the right way& wrong way to touch someone. I explain that he has no right to touch anyone and that he should never ever try to touch anyones privates again. I guess I'm wondering should i be concerned because it was more than just one child or as they say  is he just curious and it will pass most likely. Again I know he is only 5 but i dont want to just act like it doesnt matter. Any feed Back would be nice. Thank you

[amcr]

I just posted a question about the same problem. Sorry I don't have any advice. We have done the same thing. Talked about that it is not ok to do this and watch all his play time closely. Please pass along any good advice. Good luck to you!