In this task you are given a short story and a question regarding that story. You must answer the question based on the events of the story. Try to use the same words in the story to answer each question. You should completely answer the question in a short answer. Do not include information that is unnecessary to answer the question.

Robin tricked Doug into marrying her by getting pregnant. Doug divorced Robin because he loved Tracy. Tracy married Doug because they were in love. Doug found out that Tracy slept with Mr Washington. Mr Washington and Robin's baby died under mysterious circumstances.
Why did Doug divorce Robin?
Doug realized that he loved Tracy.