Fear Stress and Anger - 1x03 - Stress and Drugs
Duncan goes to see Martin and Julie to say he is having marriage problems, and when he gets home he sees Sarah sleeping with his golfing partner Barry. Duncan then changes the locks, and Sarah comes to stay with Martin and Julie in the spare room, Martin having taken Gran back to the nursing home. Sarah's presence soon causes problems all round, so Julie brings Gran back which means Sarah has to go so Gran can have her room back.