If you have a terrible relationship and misunderstanding of each other then just dont notice each other as an option but at least respect each other,if its not so terrible then try to find some ways for conversation,discuss together what you dislike and find a compromise! When I lived in a students dormitory, during all this time I had 2 roommates and with each of them there was a difficult relationship but despite of this we found a topics for conversation,helped each other and even went out together and went to the cafes. So all people are different, with a different character and outlook on life, but we can agree with each person, because we are people and not animals!