sore point, a

sore point

A topic that makes one angry or uncomfortable. Whatever you do, don't mention his ex-wife—his divorce is really a sore point with him.
See also: point, sore

sore point, a

A sensitive or annoying issue, as in Don't mention diets to Elsie; it's a sore point with her. This idiom was first recorded as a sore place in 1690.
See also: sore