phrase/a lo ˌet͡ʃo | ˈpet͡ʃo/
what's done is done; make one's bed and lie in it; own up to it
Chosen for the rhyme. Pecho literally means “chest”, but figuratively “valor, strength, fortitude”, and as a conjugating form of pechar it also means “I put up with, I deal with”. This phrase can therefore be interpreted as “to the done [thing], fortitude”, “with what's done, I deal/put up”, or less literally, “I shall deal with what's done”.