It's good to respect your roommate's space.
Trevor has a roommate who's not home and who doesn't like people going in his room.
Trevor wants to borrow a book from his roommate's room.
Trevor waits until his roommate gets home and asks to borrow the book, and they give it to Trevor.
Trevor goes into his roommate's room and goes through their things until he finds the book he wants.
Trevor's roommate is relieved that Trevor didn't go into their private room to get the book himself.
Trevor's roommate is very angry that Trevor violated their private area.