[Eternal]

They aren't being "dirtbags," they are being your parents and are just looking out for you. Games rated M are for ages 17 and up, which is four years older than you currently are. I know you feel mature enough to play these games, but try and see things from your parents point of view. There are still plenty of games you can play that aren't rated M. I wouldn't go behind their back to play those games; instead, show they you are mature and perhaps they will let you play them sooner than you think.