Kural - 1018

Though know'st no shame, while all around asha med must be:
Virtue will shrink away ashamed of thee

Explanation
Virtue is likely to forsake him who shamelessly does what others are ashamed of.

Tamil Transliteration
Pirarnaanath Thakkadhu Thaannaanaa Naayin
Aramnaanath Thakkadhu Utaiththu.