dig own grave

dig (one's) own grave

To do something that has or will have negative consequences that are easily able to be foreseen. If you don't turn in your project, you're digging your own grave. There's no way you'll get a decent grade without it! I'm afraid I'm digging my own grave by turning down the promotion.

See also: dig, grave, own

dig one's own grave

Fig. to be responsible for one's own downfall or ruin. If you try to cheat the bank, you will be digging your own grave. Those politicians have dug their own grave with their new tax bill. They won't be reelected.

See also: dig, grave, own