put the boot in idiom informal
(在对方已倒地后)继续踢打
to kick someone when they are already on the ground
雪上加霜
to make a bad situation worse, by criticizing or being unkind
After he lost his job, his wife put the boot in by announcing she was leaving him. 他失去工作后妻子又说要离开他,真是屋漏偏逢连夜雨。