Unless you're paying rent, paying your own bills, and making your own car payment.... you're living under their roof, eating their food, driving their car, soaking up their heat/ac, drinking their water, etc... so you should abide by their rules. True enough, you're old enough to make your own decisions, but until you stop milking the tit, you don't have much choice in the matter. I'm not trying to sound like a dick or anything, but until you're capable of paying your own bills, you're kinda stuck in the situation. The best thing you can do is, talk to your parents about it. Make sure that neither of you are in a bad mood when you do though, or it might pretty ugly, and you both might say some things that you will regret.