허물없이 지내다 · 허물없다 (adj.) · 허물없는 사이
casually, without reserve, like close friends
Example
우리는 어릴 때부터 허물없이 지낸 친구예요.
We're friends who've been completely at ease with each other since childhood.
Word parts
Built from 허물 'fault, flaw' plus 없이 — so close that flaws don't matter.
Good to know
Pronounced [허무럽씨]; 허물 also means a shed skin, as in 뱀 허물.