I honestly don't think they know that they were making all of us uncomfortable, but I thought it was too rude for me to tell them. This question doesn't just apply to those guests, however, it applies to all people who stay for long periods of time. Dear Dazed and Confused, You tell your guests, in the politest way possible, that they are breaking your parents' household rules. That sort of thing. House rules are things you're gonna have to get used to, especially if you go off to college and room with someone.
Rules make it easier for people to live together -even if it's just for a short while.
If your guests give bovine birth about having to follow rules, these are friends you might not want around the house anyway.