o.k. not to be mean at all, but you must do some weird things with you friends to know when the developed.
i think he is just gifted, i don't know why he was getting undressed while you were there but i think he is an early developer he could have stopped growing, im 15 and 6ft tall but have a 4 1/2 penis so that is still growing for me, but he might grow more yet
I'd have to say he probably developed early. I was almost completely developed by the time I was 12. The age varies for everyone. Most my friends were'n't fully developed until much later than me. Just different for everyone.