Final answer:
The main character's cousin is kicked out of his house for wanting to be a vegetarian in the book 'The Jungle' by Upton Sinclair.
Step-by-step explanation:
The book in which the main character's cousin is kicked out of his house for wanting to be a vegetarian is The Jungle by Upton Sinclair. In the novel, the main character, Jurgis Rudkus, is employed by various meatpackers and witnesses the unsanitary practices of the beef packing industry. The cousin's desire to be a vegetarian goes against the norms of the industry, leading to his expulsion from his house.