dig one’s own grave - do something that has or will have negative consequences that are easily able to be foreseen.

dig one’s own grave 我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我有我我有我我有我我有我我有我我有我我有我我有我我有我我有我我有我我有我我it!

I'm afraid I'm digging my own grave by turning down the promotion.

If she continues to behave like this towards her senior officer, she'll be digging her own grave.