Wearing Cop Badges As Fashion?

Hi, I have a 16 year old nephew that thinks he's a cop and wears a New York cop badge every time I see him at family reunions (which is once ever week, because he lives 4 blocks from where I am at). I have a cousin working at the New York PD hat says in his state, wearing cop badges is illegal. So, main question, is it illegal for him to do it? I mean hes not pretending to be a cop, just wearing the badge. (I am in Arlington, Virginia).