i was circumcised at birth, so i wasn't able to see a before and after haha, but i do believe it does...not a nasty scar. Google an image i guess? lol

yeah it leaves a mark not really a scar, that when you get it at birth. Burt my guys just has like a dark ring around his shaft right under the head. its not gross or anything and you cant feel it. its just a darker shade of his skin color. But an adult penis is much diffrent than a baby's.

Yes it can. Probably not as much as when you get it at birth, though. I still don't think he should do it