So, I have another (very slightly awkward) roommate story. I left my room for a minute to visit someone down the hall, and as I re-entered my room, I made a really gross coughing-up-phlegm sort of noise, not realizing that, during the five minutes I'd been gone, my roomie had gotten back from her class. I didn't realize she was in her room until she started laughing at me.

The moral of the story: Always check to make sure your roommate is not in the room before making weird noises.