First, the kid should not have seen the guy's concealed weapon... because: concealed.
Second, responsible handgun carriers typically carry them in a holster, to eliminate the possibility of lint getting into the barrel(s) (and to cover the trigger, though this design already has that covered)... and to keep them pretty. Even pocket guns get pocket holsters.
Third, I'm pretty sure this design will not be legal in some states. It puts me in mind of some laws that prevent guns that are disguised by their holsters.