Bite the biter.
More Portuguese Proverbs:
The ass's son brays one hour daily.Portuguese
A well-formed figure needs no cloak.
Portuguese
Beware of the dog that does not bark.
Portuguese
Meowing cats catch fewer mice.
Portuguese
If you laugh to-day, you will cry to-morrow.
Portuguese
Who holds his peace and gathers stones, will find a time to throw them.
Portuguese