twist / turn the knife (in the wound)

/twˈɪst tˈɜːn ðə nˈaɪf ɪnðə wˈuːnd/

to twist / turn the knife (in the wound)

to purposefully make someone suffer more than they already do

Examples

1. He said it was over, and then he turned the knife and said he had never loved me.

2. He said it was over, and then he twisted the knife and said he had never loved me.

3. Any more cuts in government aid to these poor people will be twisting the knife in the wound.

4. After the divorce, her friend turned the knife in the wound by saying she had always thought that the marriage wouldn't last.