“ Always sleep with one eye open. Never take anything for granted. Your best friends might just be your enemies. ”
Source: The Lying Game
Similar Quotes
Be like family to your friends, a friend to strangers, and a stranger to your enemies. 
Never explain- your friends do not need it and your enemies will not believe you anyway. 
It's a sad thing not to have friends, but it is even sadder not to have enemies. 
It is easier to forgive an enemy than to forgive a friend. 
In the end, we will remember not the words of our enemies, but the silence of our friends. 