I think you should find a foreskin-friendly doc as previously suggested by pp so that they can tell your son "it looks fine." If it's not fine, then that's a different story..but it sounds normal.
In the meantime, you can still talk to your son about what is normal at this age, can you even print out very simple resources to show him - two or three pages of pictures/text to explain why this might be normal. Also talk to him about the advantages/benefits and normalcy of a foreskin.
In the meantime, you can still talk to your son about what is normal at this age, can you even print out very simple resources to show him - two or three pages of pictures/text to explain why this might be normal. Also talk to him about the advantages/benefits and normalcy of a foreskin.







