I do not think that all teens have huge dicks..ok, I am from Europe, I donīt know if you americans have bigger dicks than us?..
I am 32 yo, but I remember that when I was a teen most of the boys in my class did not have a big dick. Most of them were just normal or below average...(from 4 to 6,5 inches...10 to 16-17 cm...I actually saw most of them erect in the shower!). I am not really huge, just 7 inches, but I have been the same size since I was 14 and at that age I was always one of the 1-2-3 "biggest" at my school. So NO, they were definitely not all hung!
Ok, it is 15 years ago now, maybe things could have changed. But I doubt it. Being a gay (I have to admit that hi hi) I have seen a lot of guys naked, and since the age of consent is 15 in my country (I do not remember what it is like in the USA?!), I have also been with a few teens, especially when I was a little younger myself. And they were not bigger than the older guys I have been with! All the teens I have met had a dick from 5-8 inches, some of them fairly big, others small, but most of them normal. But from my experience, they are not bigger than guys of my own age or older!