your friend is a fucking moron dude. i'd hit him in the face for telling ANYONE about the grow. fuck the girlfriend, thats HIS girlfriend and has absolutely no reason to know about YOUR grow. your buddy deserves a broken tooth.
and if dude wants to keep having the girlfriend over every night and buying a new dog and shit...tell him to get the fuck out. tell him that you're uncomfortable with the living situation and if he wants more pets and for her to be over everyday then he needs to do that in his own place.
people can act so stupidly when they're "in love"...
although i will add just for fun that one of my best friends was engaged to her man 3 months after they started dating and about 4 months after they met. that was almost 5 years ago now and they have a really great relationship. so it does happen...where people get involved quickly and actually stay together