To mention or point out someone's weak spot or sensitive issue; to touch a sore spot (often used figuratively).
会議で彼のミスを指摘して、つい痛いところを突いてしまった。
In the meeting I pointed out his mistake and unintentionally hit a nerve.
冗談のつもりが、友達の家庭の問題に触って痛いところを突いてしまった。
I meant it as a joke, but I touched on my friend's family problems and hit a sore spot.
そのインタビューは鋭くて、彼の痛いところを突いた質問が多かった。
The interview was sharp, with many questions that probed his sore spots.
風刺漫画は社会の痛いところを突くことが多い。
Satirical cartoons often hit at society's sore spots.