I'm over 20. Lots of people age 18-23 where I live. Also alcohol parties here. Some are at people's places and cost $5 to get into, and others are around the pool. Just wondering, if I go to the pool and chat with the women there, and there is beer around, and the cops show up and discover some of them are under 21, can I get in trouble? Do they have to prove that the people over 21 supplied it individually, or can they do group assumption? I don't drink.