expression, noun
weak point; sore spot; raw nerve
Refers to a sensitive topic or personal vulnerability that one does not like being touched upon. Often used in the phrase 痛いところを突く (to touch a sore spot).
彼は私の痛いところを突いてきた。
He touched on my weak point.
その質問は彼にとって痛い
That question seemed to hit a sore spot for him.