leave well alone
US /liːv wɛl əˈloʊn/
UK /liːv wɛl əˈloʊn/

1.
zostawić w spokoju, nie ruszać
to not try to change something that is already satisfactory or working well, because doing so might make it worse
:
•
The system is working fine, so it's best to leave well alone.
System działa dobrze, więc najlepiej zostawić to w spokoju.
•
I was going to redecorate, but my husband told me to leave well alone.
Miałam zamiar odnowić, ale mój mąż powiedział mi, żebym zostawiła to w spokoju.