Never regard something as doing you good if it makes you betray a trust, or lose your sense of shame, or makes you show hatred, suspicion, ill will, or hypocrisy, or a desire for things best done behind closed doors.

[Μὴ τιμήσῃς ποτὲ ὡς συμφέρον σεαυτοῦ, ὃ ἀναγκάσει σέ ποτε τὴν πίστιν παραβῆναι, τὴν αἰδῶ ἐγκαταλιπεῖν, μισῆσαί τινα, ὑποπτεῦσαι, καταράσασθαι, ὑποκρίνασθαι, ἐπιθυμῆσαί τινος τοίχων καὶ παραπετασμάτων δεομένου.]

Marcus Aurelius (AD 121-180) Roman emperor (161-180), Stoic philosopher
Meditations, Book 3, #7 [tr. Hays (2003)]
    (Source)

Original Greek. Alternate translations:

Never esteem of anything as profitable, which shall ever constrain thee either to break thy faith, or to lose thy modesty; to hate any man, to suspect, to curse, to dissemble, to lust after anything, that requireth the secret of walls or veils.
[tr. Casaubon (1634), #8]

Don't be fond of any thing, or think that for your interest, which makes you break your word, quit your modesty, be of a dissembling, suspicious, or outrageous humor; which puts you up on hating any person, and inclines you to any practice, which won't bear the light, and look the world in the face.
[tr. Collier (1701)]

Never value anything as profitable to thyself which shall compel thee to break thy promise, to lose thy self-respect, to hate any man, to suspect, to curse, to act the hypocrite, to desire anything which needs walls and curtains.
[tr. Long (1862)]

Think nothing for your interest which makes you break your word, quit your modesty, hate, suspect, or curse any person, or inclines you to any practice which will not bear the light and look the world in the face.
[tr. Zimmern (1887)]

Never esteem anything as of advantage to thee that shall make thee break thy word or lose thy self-respect.
[tr. Morgan, in Bartlett's (1894)]

Never value as an advantage to yourself what will force you one day to break your word, to abandon self-respect, to hate, suspect, execrate another, to act a part, to covet anything that calls for walls or coverings to conceal it.
[tr. Farquharson (1944)]

Never value the advantages derived from anything involving breach of faith, loss of self-respect, hatred, suspicion, or execration of others, insincerity, or the desire for something which hast to be veiled and curtained.
[tr. Staniforth (1964)]

Never value as beneficial to yourself something that will force you one day to break your word, abandon your sense of shame, hate, suspect, or curse someone else, pretend, or desire something that needs the secrecy of walls or curtains.
[tr. Gill (2013)]

Value nothing which compels you to break your promise, to abandon your honor, to hate, suspect or curse anyone, to be a hypocrite, or to lust after anything which needs walls or decorations.
[tr. @sentantiq (2019)]

Some causes will force you to betray faith, abandon shame, hate or suspect another person, call down curses, put forward explanations, or desire something that requires walls and fences. Do not regard these causes as necessary or beneficial to yourself.
[Source]