Kural - 145

'Mere triflel' saying thus, invades the home, so he ensures
A gain of guilt that deathless aye endures

Explanation
He who thinks lightly of going into the wife of another acquires guilt that will abide with him imperishably and for ever.

Tamil Transliteration
Elidhena Illirappaan Eydhumenj Gnaandrum
Viliyaadhu Nirkum Pazhi.