Ramayana
अस्मि यदवोचस्त्वमेकपत्नीष्वयं क्रमः । एवमुक्त्वा स तां रक्षो निवेश्य च शिलातले । कामभोगाभिसंसक्तो मैथुनायोपचक्रमे ॥ 7-26-42 ॥
" .regarding what you have said, that this rule applies to women who have but one husband." Having spoken thus, that rakshasa, laying her down upon the surface of a rock and given over to the enjoyment of lust, set about coupling with her.
english translation