When someone says something perhaps cruel or unkind about someone, even if it's true, we would say that's " below the belt, " that's not playing by the rules, not being nice.
" Below the belt" is a common expression, and that usually means someone who is doing something in a competition or in a fight, especially in sports, that is illegal – that is not allowed.
“Below the belt” 一个常见的表达方式,通常意味着某人在比赛或打架中做某事, 尤其在体育运动中, 这非法的——这允许的。