Hi, I'm 13 and have been masturbating for a couple of years now. I was wondering if it's normal for a penis to grow larger with masturbation, because mine right now is larger than a 17-year-old's average size.

Dude,

If masturbation made a penis larger, most of us guys would need a wheel barrow just to walk a few yards.

As for what a "17-year-old's average size" is, I have no idea. But you've clearly been looking, so I leave that one up to you.

Paul
author of "Guide To Getting It On!"

if you are interested in Paul's book:
http://www.amazon.com/exec/obidos/ASIN/1885535694/goofyfootpres