mindseye: *nods* A boys' size 10 underwear is very small. Anyone who's experiencing a puberty so precocious that they're having clothing problems already at that age and size has much more serious medical problems than can adequately be discussed here.
BagOfBones, if by some sliver of a chance, you are telling the truth -- talk to your mommy and daddy and have them take you to see an endocrinologist. (That's a pretty big word, so you could just say 'doctor'.)
Otherwise, keep tipping your hand -- I'm sure the FBI will catch up with you pretty soon at the rate you're going.