foul your own nest

foul (one's) own nest

To do something that causes problems for oneself. I'm pretty sure I fouled my own nest when I accidentally insulted the boss's daughter at the holiday party.

foul one's (own) nest

To do something that creates problems for oneself. I wouldn't talk to the boss while you're angry—you'll just end up fouling your own nest.

foul your own nest

LITERARY

If someone fouls their own nest, they do something which harms themselves and damages their chances of success. Man has invented a hundred ways of fouling his own nest — the grime, the pollution, the heat, the poisons in the air, the metals in the water.

foul your own nest

do something damaging or harmful to yourself or your own interests.

The proverb it's an ill bird that fouls its own nest , used of a person who criticizes or abuses their own country or family, has been found in English since the early 15th century.