믿는 도끼에 발등 찍혔어요 · 믿는 도끼에 발등 찍힌 기분이에요
to be betrayed by someone you trusted; stabbed in the back by a trusted person
Example
가장 친한 친구가 비밀을 말하다니, 믿는 도끼에 발등 찍혔어요.
My best friend told my secret; I got stabbed in the back by someone I trusted.
Word parts
Literally 'the axe you trusted chops your own foot.'
Good to know
Usually in the past tense: 믿는 도끼에 발등 찍혔다.