Dear Amy: I’m dealing with a tough situation with my new roommate (I did not know her prior to her moving in). She moved into the apartment in September and has been sleeping with a guy who is engaged since then. Her boyfriend lives with his fiancée but sleeps over twice a week at our place. He has lied multiple times about the direction his relationship with his fiancée is going, and he finds us while we are out and trying to have a good time.