It's not just ONE talk, it's an ONGOING line of communication.
If their underwear or swim trunks cover it?
NO ONE touches it.
NO ONE should ask to see it - except for a Doctor with ME present.
it's NOT about a stranger - as evidenced here - more molestations are done by a known family member, sports coach, teacher, etc. this way - they can tell the victim that "their mom or dad won't believe them" or "It's our little secret".
Tell your son that NO ONE is allowed to touch his p****** p****..they are HIS p****** p****...COMMUNICATE with him on HIS level - not an adult level - tell him that NO adult should ask him, a child, to help him find a puppy.
No adult will be allowed to pick him up from school.
Set a password that is ONLY known to you guys - that wouldn't be obvious to someone else - like the name of his teddy bear - and if an adult were to come to somewhere and pick him up - he needs to ask "what's the password?" and if they don't know it - then he's NOT to go with them... you can use that later if you wish - but the gist is that this is NOT just ONE talk. It's an insert in many conversations.
GOOD LUCK!