Your parents are young and healthy. However your mother-in-law has suddenly become ill. Your wife wants to bring her mother to live with you until she feels better and can go back home to live independently. Your plan was that you would take responsibility for your parents and your wife would take responsibility for hers. There was never an idea of co-mingling or sharing the responsibility for care. While you hesitantly agreed to allow your mother-in-law to live in your home short term, you feel resentful. Why should you care for someone who is not truly your family?