Syngenesophobia: This phobia refers to the fear of relatives.
Hey you newlyweds, pay attention! I have just given you a reason to avoid your mother-in-law. In case you missed it, here is an example:
Mother-in-law: “Hello, son.”
Son-in-law: “Sorry, but you can’t be around me. I have a condition called Syngenesophobia.”
Mother-in-law: “What does that mean?”
Son-in-law: “It means you have to leave. Now.”