“Friendship's enemy is betrayal.”
“Friendship is one friend betraying another friend to a third friend. With a fond friendly smile. The greater the betrayal, the greater the intimacy - the greater the friendship.”
“Conformity is the enemy of friendship”
“Absence is the enemy of love and the friend of friendship.”
“Thy friendship oft has made my heart to ache: do be my enemy for friendship's sake.”
“You cannot be betrayed by your enemies, only your friends.”