Fuck it man, just find out what your parents' fears about pot are and hit them there. That sentence was meant to be ironic, but it spurred me on to think of a solution. Your parents are clearly cool having the babybabybabies in the house as far as the law's concerned.They don't seem to be that pissed off at you, share the fucking love. Tell them why you enjoy smoking, you're likely to be a youngster, beam the lovely youth they love at them, then introduce the young adult. Responsible young adult..who grows lethal drugs at his parents' house. Deadly deadly weed. Eh kidding.
Hey, i in no way intend to be patronising, but clearly you're in a transitory thing and haven't cut the apron strings yet, or ever, sheeeaht, those mommas got a hold on we; fuck i'm 37 and i still gat no choice when it comes to momma!
Scrub that last bit please; my Dad keeps showing me pictures of the moon.
Why not have a sit down with your folks that you initiate, tell them why you smoke, why you grow. Have a chat. Maybe your Mum and Dad are cool, but don't want to encourage you to smoke. Please take only one thing from this; speak to your folks.