lady_bird..
don't get confused.. you must understand that your bro's friend is
in the wrong.. i wouldn't be wandering around someone's house and
entering into someone's room even if the door was wide open..
it's really a matter of privacy.. it doesn't matter if you did or
did not show your objection there and then.. what that guy did was
totally sickening and disrespectful.. both to you and to your
brother..
anyway, don't feel guilty about what happened.. it's not your
fault.. just be careful the next time.. 
