Is it safe to let a girl lick your penis under the age of 13?

If you are a thirteen year old boy that wants to do this I would say It is frowned upon by the norms of society and is can land you in trouble. It is definitely illegal if that vagina is older then 16. I personally think you should wait a few more years before contemplating the move. From the Physical point of view as long as no one has any diseases that can be passed on it cant do any harm. Above all Don't let any one pressure you into doing something you don't want to do