from the words of the early prophets: If you feel no shame, then do whatever you wish
Abu Mas‘ūd al-Ansāri (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "Indeed, some of what people learned from the words of the early prophets: If you feel no shame, then do whatever you wish.”
From the wise traditions of the previous prophets is enjoining bashfulness. Bashfulness is a quality that drives one to do whatever adds beauty and adornment to his character and avoid whatever causes defamation and disgrace. It is one of the characteristics of faith. So, if bashfulness – which is part of faith – does not deter one from committing that which disgraces him, then what else can deter him?