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.

Common Names:

Name	Pronounced	Usage
Dathan	-	Biblical
Mstislav	mstee-SLAHF (Russian)	Czech, Russian, Medieval Slavic
Patience	['peiʃəns]
AndrÉE	awn-DRE	French
Nazarius	-	Late Roman
Allissa	ə-LIS-ə	English (Rare)