Maybe I'm psychotic, but I love telling my kids no (14,9, and 6) for things they just assume I'll be ok with. I've been to plenty of parties in high school that were certainly to big for the location (city living). There was only one house that the parents were home and just ignored what we were doing. Every other party the parents were out for the night or on a trip. It's insane to me that parents would be ok with a bunch of crazy teenagers hanging out at their place and then also be cool with alcohol consumption. I'd be shutting that down asap.