Are there any real “Red Flag Books”?

I was talking to a friend of mine the other day, we were talking about our dating life’s (or lack there of, in my case) she was telling me about this guy she had been on a few dates with. She told me that things were going well and they got talking about books, he mentioned he had just finished reading Tropic of Cancer (a book I’ve yet to read) apparently that gave her “the ick” and is apparently a “red flag”.

I understand that everyone has their own tastes but she said to me that he was literally perfect but the fact he read this book and liked it gave her the ick