You know I'm thinking about when I was that young and yes I cross dressed then, but more pantyhose and heels and every now and then a skirt or dress but... if I would have been "out" and admitted that I crossdress I think the way you are handling it is reasonable.. I think if he gets comfortable around his family that he might eventually be able to go out in the public places, and this might or might not be what you want but for him.. as for all cross dressers it is a form of expression.. the inner self.. please don't think of him as something is wrong, that "where did we go wrong as parents" saying.. you didn't do anything wrong, this is just how some guys are.. and there are more closeted cross dressers (I am one) than are out of the closet, and your son is out to you and family and might not be a bad thing.. it could be worse...