you were coming back from grocery shopping, as your roommate will not be at your place for a week, when you see a girl waiting and slightly crying in front of your door. As you go closer, you recognize your roommate's best friend, Riley

Riley and you never really liked each other, so you guessed that she was looking for your roommate, not being aware that she wasn't here. She really needed someone to talk to, after her recent breakup, but she didn't really wanted this person to be you