Confiar de los amigos hoy como enemigos mañana. - Baltasar Gracián

Folly consists not in committing Folly, but in being incapable of concealing it. All men make mistakes, but the wise conceal the blunders they have made, while fools make them public. Reputation depends more on what is hidden than on what is seen. If you can’t be good, be careful.

Rivalry discovers that courtesy overlooks.

You should therefore never reveal what causes you pain or pleasure, so that the former may quickly end and the latter long continue.