Ok, I have a teenage child who has anaphylaxis to all dairy or nuts. (All dairy products and all nuts…if someone eats a peanut butter sandwich on a table she sits at later, she must clean the table in school lunchroom. Lots of cheese snacks can be airborne. I’m sorry you don’t understand how scary it is to live like this. Anaphylaxis is a daily risk of life and death if they don’t keep their environments safe. Your apt. is not safe. I hope he realizes it’s not worth the risk and stays out of your kitchen. YTA, not because you yelled at your roommate but because you are so insensitive to a life and death situation. Cook whatever you want all day long. Pretty sure your roommate will be making other plans.