This does happen to some men; it's not necessarily abnormal. As long as you are able to use the bathroom, and as long as your erect penis functions normally, then I wouldn't worry much.

it is embarrising though, when walking through a locker room.

Then again, if he's a grower, and an impressive one, then he could aways just... show off.

Besides, who wanders naked through lockerooms anymore!? Women certainly don't.

I have that too. It's called hidden penis. I've read on the internet that it's caused by an over zealous circumcision. My wife's OB told me not enough was taken off. I tend to believe her. There does seem to be a sheath where I can take the excess skin and roll it up towards the glans.

I wish it would just hang there instead of doing that damn turtle thing.

that just smaller then average

Not necessarily. His flaccid penis hides... but for all we know, he's 6 inches when erect and that's what really matters!