touch (one) on the raw
To do or say something (such as mentioning a sensitive topic) that causes one to feel angry, agitated, or self-conscious; to touch a nerve. Primarily heard in UK. I accidentally touched Vanessa on the raw by mentioning her new haircut—apparently, she's really unhappy with it. Your column must have touched the mayor on the raw, because we've been served with a defamation lawsuit from his office. I could tell she was touching Jack on the raw when she brought up his former employer.
touch someone on the raw
upset someone by referring to a subject about which they are extremely sensitive.