Al perro que duerme, ¡¡¡no lo despiertes!!!

 …LET SLEEPING DOGS LIE…

If someone is told to let sleeping dogs lie, it means that they shouldn’t disturb a situation as it would result in trouble or complications.

Refrain from disturbing people or from debating topics not currently causing one any trouble.

Example: It may be that he used to live with Miss Bloggs; but I don’t think you ought to refer to that topic in front of his wife – it’s better to let sleeping dogs of that sort lie.

Other Proverbs

To turn the tortilla around
No hay mala cocinera con tomates a la vera
Lo que agosto madura, septiembre lo asegura
Agua de febrero, llena el granero