below the belt

US /bɪˈloʊ ðə bɛlt/
UK /bɪˈloʊ ðə bɛlt/
"below the belt" picture
1.

卑鄙的, 不公平的, 人身攻击的

unfair or cruel, especially in a way that is too personal

:
His comment about her past was really below the belt.
他对她过去的评论真是卑鄙
That joke was a bit below the belt, don't you think?
那个笑话有点卑鄙,你不觉得吗?