Eh, don't fuck your brother over. I agree with rollingKansas. Your brother isn't trying to be a dick he is against you smoking because he cares about you. Whether or not its justified to be anit-weed is up for debate, but he isn't doing it just to be a hard ass. Karma is a bitch, you don't want to fuck with him just because he was "looking out for you." For better or worse he was trying to help, you would be trying to hurt if you fucked him over. Best to just move your stash elsewhere. Plus if they find a glass piece in his room they may still smash/confiscate it.

DENY DENY DENY, and move your stuff to a friends house.